Simple Future and Conditional form

I've combined both Future and conditional form into one section as they both follow similar form. Simple Future form is sentences like "I will do this". Simple Conditional form is sentences like "I would do this". They both are referring to things in future though one is hypothetical. Both of these transformations keep the base word same, and just add a suffix. So, remember that if the full infinitive form of the verb is kept, it's always things in future !! The transformation of all verbs (ending in -ar, -er, -ir) is the same, so it's easy to remember.

Similarity with Past tense: One caveat is that past tense for 3rd person plural for -ar verbs ends in -aron. This may make it sound like the full ar verb is being used, and we are just adding -on to it. So, we may confuse it with future form. The only thing that saves us here is that past tense ends in -on, while future form for 3rd person plural always ends in -án (and NOT -on). 

ex: hablar: past tense for 3rd plural is hablaron, while that for future tense is hablarán (with accent). So, remember this subtle difference.

l


 

Future Tense of -ar, -er, -ir verbs:

Fortunately future tense of all the -ar, -er, -ir verbs follow the same pattern. However, there are many exceptions to this rule that we will learn later. Future tense is "I will go", "she will go to Paris" etc. There is no separate translation for "will" in spanish, we just transform the verb based on table below to indicate "will go", "will eat" in 1 word.

Lesson 51 => https://www.youtube.com/watch?v=U42loE1zhdw

Below is the transformation table. The thing that is different about future tense is that the base word remains the same, we just add the below suffix to it. The suffix has an accent in all forms except first person plural.

 base word = -ar, -ir, -er singular plural ( add s at end)
 I => First person -é (with accent)

-emos (same as -er verb)

You (informal) => Second person

-ás (with accent)

-éis (same as -er verb)

He, she, You (formal=> Third person

-á (with accent)

 

-án (with accent)

 

Viajar => To travel: The Spanish verb viajar is an -ar verb translated in English as “to travel”. Below is the table based on above transformation.

 

 base word = viajar (to travel) singular plural ( add s at end)
 I => First person

viajaré => will travel

viajaremos

ex: nosotros viajaremos (we will travel)

You (informal) => Second person

viajarás

viajaréis

ex: vosotros viajaréis => You will travel

He, she, You (formal) => Third person

viajará =>

 

viajarán =>

 

Ex:

  • I will go tomorrow => yo iré mañana
  • She will talk to her boyfriend tonight => Ella hablará con su novio esta noche
  • I'll find a nice house some day => encontraré una casa bonita algún día => Here we used "casa bonita" as adjectives come after noun in Spanish. However, "una bonita casa" is also valid.

 


 

Conditional (condicional simple) of -ar, -er, -ir verbs:

This is closely related to future form. But it's used to talk about hypothetical situations and make requests. Ex: "Would you pass the water?", "We would like out the trash", etc. Jus tlike future tense, all -ar, -er, -ir verbs follow the same pattern and base word remains the same (we just add suffix based on table below). There is no separate translation for "would" in spanish, we just transform the verb based on table below to indicate "would like to", "would you pass" in 1 word (just as in Future tense).

"Could" is another conditional form just like "would". ex: It could rain tomorrow. It's base verb is "can" or "poder" in spanish. So For could, we have separate verb "poder" to translate, while for "would" we have no separate verb, but instead conjugate the verb that follows "would".

Below is the transformation table. Here too the base word remains the same, we just add the below suffix to it. The suffix has an accent in all forms on the letter "i" (only the 1st i in suffix).

NOTE: This suffix "ía" etc is the same as that used in "Past Imperfect form" (i.e used to go, etc). The only difference is that it goes with the full base word here (i.e gustar + ía = gustaría), while in Past Imperfect, it goes with the stem (i.e gust + ía = gustía)

 base word = -ar, -ir, -er singular plural ( add s at end)
 I => First person -ía (with accent on i)

-íamos (same as -er verb)

You (informal) => Second person

-ías (with accent on i)

-íais (same as -er verb)

He, she, You (formal=> Third person

-iá (with accent on i)

 

-ían (with accent)

 

Conocer => To know: The Spanish verb conocer is an -er verb translated in English as “to know”. Below is the table based on above transformation.

 

 base word = conocer (to know) singular plural
 I => First person

conocería => I would know

conoceríamos

ex: nosotros conoceríais (we would know)

You (informal) => Second person

conocerías => you would know

conoceríais

ex: vosotros conoceríais => You all would know)

He, she, You (formal) => Third person

conocería => he/she/you would know

 

conocerían =>

 

 

Ex: (NOTE: no separate transformation for would, the verb following "would" is conjugated based on table above)

  • I would go tomorrow => yo iría mañana
  • She would like to read this book => ella le gustaría leer este libro
  • I would like to order a pizza => me gustaría ordernar una pizza

 

Poner => Can: The Spanish verb poner is explained under -er verb. It's conditional transformation is "could" and used very often, i.e it could rain tomorrow, etc. Below is the table based on above transformation. Stem is "podr" instead of poner for future tense.

 

 base word = poner (to know) singular (stem is podr) plural
 I => First person

podría => I could

podríamos

ex: nosotros conoceríais (we could)

You (informal) => Second person

podrías => you could

podríais

ex: vosotros conoceríais

He, she, You (formal) => Third person

podría => he/she/you could

 

podrían =>

 

 

ex: NOTE: Here "could" is conjugated based on table above, the verb following it is kept in infinitive form)

  • It could rain tomorrow => podría llover mañana
  • I could do it => yo podría hacerlo
  • You could go => tú podrías ir
  • could you pass me the salt? =>  ¿podrías pasarme la sal?
  • Could you tell me the time? => ¿podrías darme la hora?

 


 

 

Past Tense of -ar, -er, -ir verbs:

Past tense of -ar verbs follow a different pattern than past tense of -er/-ir verbs, which follow the same pattern., -er, -ir verbs follow the same pattern.

Past Tense of -ar verbs:

General transformation remains almost same as present tense.

Lesson 31: https://www.youtube.com/watch?v=ZwTPwRMjLD8

 

 base word = -ar (to do something) singular plural ( add s at end)
 I => First person -é (with accent)

-amos (same as present tense, figured from context)

You (informal) => Second person

-aste (te added compared to present tense)

-asteis (-is added to singular form instead of áis)

He, she, You (formal=> Third person

-ó (with accent. -o w/o an accent was the present tense for Singular First person)

 

-aron

 

Hablar => to speak

 base word = hablar (to speak) singular plural ( add s at end)
 I => First person

hablé

ex: Yo hablé => I spoke

hablamos (Same as present tense, figured out from context)

ex: nostros hablamos => We spoke

You (informal) => Second person

hablaste

ex: tú hablaste =>you spoke

hablasteis

ex: vosotros hablasteis

He, she, You (formal) => Third person

habló

ex: Ella habló => She spoke

 

hablaron

ex: Ellos hablaron => They spoke

 

Gustar => to speak

 base word = gustar (to speak) singular plural ( add s at end)
 I => First person

gusté

ex: te gusté me => you liked me

gustamos

ex: te gustamos => you liked us (same as you like us)

You (informal) => Second person

gustaste

ex: le gustaste te=> he liked you

gustasteis

ex:  ex: He liked you all => le (to him) gustasteis

He, she, You (formal) => Third person

gustó

ex: I liked the car => Me gustó el coche (here car is 3rd person, so gustó used)

gustaron

ex:I liked peoples => Me gustaron los pueblos

 

 

Past Tense of -er/-ir verbs:

General transformation for past tense remains almost same as present tense.

Link: https://www.youtube.com/watch?v=P1i5BrPAELU&list=PLv63dFTP4Sjq6knRsZQI-bTnRE38cZZoy&index=26

Link (lesson 35) => https://www.youtube.com/watch?v=oCT68wkVCNM

 

 base word = -er/-ir singular plural
 I => First person

-imos

You (informal) => Second person

-iste

-isteis

He, she, You (formal=> Third person

-ió

 

-ieron

 

Comer => To eat. Past tense is "ate".

 base word = comer (to eat) singular plural ( add s at end)
 I => First person

comí

ex: Yo comí manzana=> I ate apple

comimos

ex: nosotros comemos (we eat)

You (informal) => Second person

comiste

ex:

comisteis

ex: vosotros comisteis

He, she, You (formal=> Third person

comió

ex: Ella comió => She ate

 

comieron

ex: Ellos comieron

 

Haber => had. Past tense of has is had. It's used as an auxilary verb. Haber is an irregular form, and so doesn't follow regular -er table. For transformation purposes, base stem is "habí" (i with an accent), and the verb itself follow ar verb Present tense table (instead of Past tense -er table).Actually Haber changes to Habíar, and hence is an -ar verb. The only odd entry is 1st person singular which has -a instead of -o.

 base word = haber => Habíar (had) singular plural ( add s at end)
 I => First person

había (instead of -o, it ends in -a, so it becomes same as 3rd person singular)

habíamos

You (informal) => Second person

habías

habíaís

He, she, You (formal) => Third person

había

 

habían

 

Escribir => To write. Past tense is 'wrote".

 base word = escribir (to write) singular plural ( add s at end)
 I => First person

escribí

ex: Yo escribí => I wrote

escribimos

ex: nosotros escribimos (we write)

You (informal) => Second person

escribiste

ex: tú escribiste

escribisteis

ex: vosotros escribísteis

He, she, You (formal=> Third person

excribió

ex: Ella escribió => She wrote

 

escribieron

ex: Ellos escriben

 

 


 

 

-ir verbs: A lot of words ending in -ir are verbs and are called -ir verbs. ex: escribir => to write, etc. This is different than "ir" standalone verb that we saw above.The base word literally means "to eat". The transformation is same as "-er" verb, except for nosostros and vosotros. Here "emos" becomes "-imos" and "-éis" becomes "-ís".

Link: Same video fo -er verb above has -ir verb explanation.

 

 base word = -ir (to do something) singular plural ( add s at end)
 I => First person -o (same as -er)

-imos (instead of -emos)

You (informal) => Second person

-es (same as -er)

-ís (instead of -éis)

He, she, You (formal=> Third person

-e (same as -er)

-en (same as -er)

 

Ex: Below are few examples of -ir verbs that follow the pattern above.

escribir => To Write: The Spanish verb escribir is an -ir verb translated in English as “to write”. It looms similar to word "scribe" in English which referred to a person employed to make written copies of documents. Basically writing things by hand. Below is the table based on above transformation.

 

 base word = escribir (to write) singular plural ( add s at end)
 I => First person

escribo

ex: Yo escribo => I write

escribimos

ex: nosotros escribimos (we write)

You (informal) => Second person

escribes

ex: ¿tú escribes espanol? => Do you write spanish? => We usually omit " tú", so more common is ¿escribes espanol?

escribís

ex: vosotros escribís

He, she, You (formal) => Third person

excribe

ex: Ella escribe => She writes

 

escriben

ex: Ellos escriben

More words:

  • abrir => to open, Opposite word is cerrar => to close. Adj form is: abierto(s)/abierta(s). ex: The door is open => la puerta está abierta
  • aburrir => to bore. This word is very commonly used in past tense, or in gerund (-ing) form with both forms adding -ida/ido as conjugation. You may think of word "bored", "boring" as an adjective too, so aburrido/aburrida used aa an adjective.
    • ex: The movie is boring => la peculia es aburrida (used an as adjective, i.e movie is nice, movie is bad, etc)
    • ex; I'm bored => estoy aburrida/aburrido. Used in past participle form (i.e I had been bored, or I was bored, already happened), or you can also think of bored as an adjective (i.e I'm happy, I'm sad, etc).
  • cambiar => To change or to exchange something. ex: I want to change my hair color => yo quiero cambiar el color de mi pelo (change color of my hair)
  • coincidir => to agree (remember as to coincide or come together), diferir => to differ or disagree.
  • decidir => To decide
  • dormir => to sleep. It's similar to "dormant" so implies being dormant or sleepy. Opposite word is despertar => to wake
  • mentir => to lie.
  • ocurrir => To occur
  • recibir => To receive. Opposite of this is enviar => to send
  • repetir => to repeat. From English word, repeat.
  • sentir => to feel. Similar to Sentiment or feelings. Sentir is also used to mean "to feel or to be sorry", i.e sentimos => We are sorry for ..
  • seguir => to follow (like to follow signs, follow someone). It's mentioned on many road onstruction sign boards.
  • permitir => to allow. From English word, permit.
  • vivir => to live. Opposite word is "morir" which means "to die". morit sounds like morbid, which means dead. Noun derived from vivir is "vida" => Life. Viva is a 3rd person imperative verb, meaning live (see in imperative verb section)

 

The personal "a" (pronouned "aa"):

In short, personal "a" is used after the verb, if the verb is being done to a person. More details on this in video above (for "-er" verb).

ex: I see Maria => Yo veo a Maria. "ver" is an -er verb which means "to see". So, for "I see", it should have been "yo vo", but it's that "irregular verb", which translates to "veo". Reason might be that "vo" is too short of a word, so "veo" was kept.

 

 


 

 

-er verbs: A lot of words ending in -er are verbs and are called -er verbs. ex: comer => to eat, etc. The base word literally means "to eat". The transformation is same as "-ar" verb, except that instead of "a" in transformation, we use "e".

Present Tense:

Link: https://www.youtube.com/watch?v=P1i5BrPAELU&list=PLv63dFTP4Sjq6knRsZQI-bTnRE38cZZoy&index=26

 

 base word = -er (to do something) singular plural ( add s at end)
 I => First person -o

-emos

You (informal) => Second person

-es

-éis

He, she, You (formal=> Third person

-e

 

-en

 

Ex: Below are few examples of -er verbs that follow the pattern above.

Comer => To Eat: The Spanish verb comer is an -er verb translated in English as “to eat”. The noun "comida" meaning "food" is derived from this. Below is the table based on above transformation.

 

 base word = comer (to eat) singular plural ( add s at end)
 I => First person

como (como also means to like)

ex: Yo como manzana => I eat banana

comemos

ex: nosotros comemos (we eat)

You (informal) => Second person

comes

ex: ¿tú comes carne? => Do you eat meat (carne is similar to carnivore)? => We usually omit " tú", so more common is ¿comes carne?

coméis

ex: vosotros coméis

He, she, You (formal=> Third person

come

ex: Ella come => She eats

 

comen

ex: Ellos comen

 

Desire, Ability and Obligation verbs: All 3 are -er verbs and are one of the most used words in talks. They are discussed under irregular verbs

  • tener => have: to have or have to. Under irregular verbs. 
  • querer (kay-rer) => want:  Under irregular verbs.
  • poder => can  Under irregular verbs.

 

  • hacer => to do/to make : Under irregular verbs.
  • haber => has/have :This is discussed under participle form of verb.

 

Other -er verbs:

  • aprender => to learn. ex: we learn spanish =>  nosotros aprendemos español => we may leave "nosotros" as is common, so just "aprendemos español"
  • comprender => To comprehend or understand. Another verb "entender" is synonym to this.
    • Ex: No comprendo => I don't understand. (1st person as -o)
    • Ex: ¿Comprendes? => Do you understand?¿ (You is left out as is common, -es implies 2nd person)
    • Ex: I don't understand everything you say => yo no entiendo todo lo que tú dices. (entender stem is "entiend")
  • creer (CRE-ER) => To think or believe. Another similar word crecer, means "to grow".
    • We believe in God => Creemos en dios (el dios => the god, la disoa => the goddess)
    • I grew up in India => yo crecÍ en India
  • prender => to switch on
  • barrer => to sweep. ex: ¿Quién barre? => who sweeps?
  • nacer => to born. ex: I was born in India => yo nacÍ en India
  • romper => to break something. Adjective "roto" means broken.
  • vender = to sell (comprar=> to buy). vendedor => salesperson (vende is to sell, so related to sales)

 


 

Audio Bus interface

This section talks about communication i/f to xfer audio data. The audio genrating source are microphones, while speakers deliver that audio. In the past, microphones and speakers used to be analog sensing device, and their chip output was analog signal. However, analog signals being iprone to interference on PCB are never a preferred solution. So, now these microhones/speakers have a lot of analog logic on these chips itself, along with digital circuitry that can drive out these audio signals in digital binary format(string of 1's and 0's).

There are many different standards for transmitting digital audio data from one place to another. Some formats, such as I2S, TDM, and PDM are typically used for inter-IC communication on the same PC board. Others, such as S/PDIF and Ethernet AVB are primarily used for data connections from one PCB to another through cabling.

Audio BandWidth: Typical Audio data is sampled at 8KHz to 192KHz. It has 8bit to 32 bit resolution. For 8Khz and 8 bit resolution, we need 8k*8=64kHz bus frequency, or as high as 192k*32=6Mhz. As such, a lot of these interfaces don't need to run faster than few MHz.

Techincal doc by Analog Devices about I2C, TDM and PDM => https://www.analog.com/media/en/technical-documentation/technical-articles/MS-2275.pdf

I2S:

I2S is called Inter IC sound, and is the most common  digital audio format used for audio data transfer between ICs. The I2S standard was introduced by Philips Semiconductors (now NXP) in 1986 and was revised in 1996

Philips was bought NXP, and so bty he spec is mainatined y them here: https://www.nxp.com/docs/en/user-manual/UM11732.pdf

The attached diagram shows the waveform/connections.

FIXME ATTACH DIAGRAM --

 

I2S devices can either be in Master or slave mode. Master always drives Clock and Channel Select. Data can be driven either by Master or slave. There are 3 wires for I2S:

  1. Clock => SCK (serial Clk) or BCLK (Bit clk). Master drives SCK.
  2. Channel Select => WS (Word select) or LRCK (Left Right clk) or FS (Frame Sync). I2S can carry 1 or 2 channels of data. That channel is selected via this line, and it also serves to synchronize the frame (i.e it indicates start/end of current frame). 0= Left channel, 1=Right channel. It's better to think of WS as "Frame sync", as when you have > 2 channels, then WS will be a pulse, and in that case, it will indicate start of new frame. Master drives WS.
  3. Data => SD (serial Data) or SDATA, SDIN, SDOUT. Either Master or slave may drive SD. However, SD is unidirectional - either master or slave drives it, but has to be configured beforehand as an i/p or o/p.

Apart from 3 wires, it may have variations where following lines are added. These signals are not part of spec, but added by certain companies for their product (and commonly supported).

  1. Master clock => MCK (typically 256 x LRCLK) = commonly included for synchronizing the internal operation of the analog/digital converters. Master drives MCK along with WS.
  2. Multiplexed data line for upload => Having dedicated SDAT lines for i/p and o/p. So, instead of 1 SD pin, we have 2 separate data pins with fixed direction => SDIN and SDOUT.

 

TDM:

When we talk about I2S, we are usually talking about legacy mode I2S as explained above. I2S can also operate in a Time Division Multiplexing (TDM) mode. We use this when we want to xfer more than 2 channels of data. That is not supported by legacy I2S. We can have multiple data i/p or o/p pin with 1 set of SCK and WS (might need multiple WS?). This will solve our problem of transmitting multiple channels. But that will increase the number of pins in system. Instead we want to use single data line for transferring audio signals from all channels. This is where TDM spec comes in. There is no standard for TDM interfaces, so ICs have their own slightly-different flavor of a TDM implementation. Since TDM has no spec, a common implementation includes all 5 signals used in I2C above: BCLK, LRCK, SDIN, SDOUT and optional MCK.

A TDM data stream can carry as many as sixteen channels of data and has a data/clock configuration similar to that of I2S. Each channel of data uses a slot on the data bus that is 1/Nth the width of the frame, where N is the number of channels being transferred. A TDM frame clock is often implemented as a single bit-wide pulse (rather than I2S’s alternating High and low for left and right channels). So, at start of WS pulse, we send fixed width of data for all N channels one after the other (called a frame), and then start of next WS pulse, we send next bits of data for all N channels and so on. Thus we avoid having multiple Data Lines. Clock rates are higher here at multi MHz (although < 25MHz) as multiple channels are supported on a single data line, so higher BW needed.


TDM is commonly used for a system with multiple sources feeding one input, or one source driving multiple devices. In the former case, each TDM source shares a common data bus. The source must be configured to drive the bus only during its appropriate channel, and tri-state its driver while the other devices are driving the other channels.

 

PDM:

PDM is another variation of I2S, where 2 channels are supported by using only 2 wires => Clk and Data. 2 PDM sources drive a common Data Out (DOUT) line which feeds into the PDM receiver's DIN line. A clock generated by the system master can be used by two slave devices, which use alternate edges of the clock to output their data on a common signal line.

PDM basics:PDM is Pulse Density Modulation. Here Audio data amplitude is represented via only 1 data line, by modulating the density of 1's and 0's to indicate higher or lower amplitude. When more 1's aretransmitted, then it's indicating a higher amplitude, and when more 0's are transmitted, it's indicating a low amplitude.

https://users.ece.utexas.edu/~bevans/courses/rtdsp/lectures/10_Data_Conversion/AP_Understanding_PDM_Digital_Audio.pdf

A PDM-based architecture differs from I2S and TDM in that the decimation filter is in the receiving IC, rather than the transmitting IC. The output of the source is the raw high sample rate modulated data, such as the output of a Sigma-Delta modulator, rather than a decimated data, as it is in I2S.

 


 

MEMS Microphone:

MEMS (Micro-Electro-Mechanical Systems) microphones come in a package (just like other chips). There may be analog or digital MEMS microphone. Analog ones produce an output voltage that is proportional to the instantaneous air pressure level. They have just 3 pins => VDD, Gnd and Output Voltage pin. This output pin is connected to a microcontroller on a PCB, which processes this analog o/p and produces bits. AIn a digital microphone, the whole circuitry to process the analog o/p and produce digital bitstream is put in a single package. So, it's lot better performance in terms of noise immunity.

Basic intro: https://www.edn.com/basic-principles-of-mems-microphones/

Digital Microphone Teardown: https://www.signalessence.com/blog/mems-microphone-teardown

There are 2 separate dies inside a digital mems microphone:

  1. Microphone die: This die has the microphone accoustic sensor. This is made using same semiconductor production lines that is used for making transistors. Layers of different materials are deposited on top of a silicon wafer and the unwanted material is then etched away, creating a moveable membrane and a fixed backplate over a cavity in the base wafer.  The sensor backplate is a stiff perforated structure that allows air to move easily through it, while the membrane is a thin solid structure that flexes in response to the change in air pressure caused by sound waves. MEMS microphones need to have a hole in their package to allow sound to reach the acoustic sensor. 
  2. ASIC die: This die is a digital/analog ckt that has a charge pump to place a fixed charge on the microphone membrane.  The ASIC then measures the voltage variations caused when the capacitance between the membrane and the fixed backplate changes due to the motion of the membrane in response to sound waves.  An ADC inside the ASIC converts the voltage variations into digital format for processing and/or transmission. Finally o/p is sent out in digital format using I2S, TDM, PDM. PDM data is captured by separate microcontroller/processor, which then decides what to do with it. Typically it converts PDM into PCM via dedicated hardware filters or in software and then it finally plays on speakers.

 

The microphone accoustic sensor itself is on silicon wafer, fabricated on semiconductor production lines using highly automated processes. Layers of different materials are deposited on top of a silicon wafer and the unwanted material is then etched away, creating a moveable membrane and a fixed backplate over a cavity in the base wafer.  The sensor backplate is a stiff perforated structure that allows air to move easily through it, while the membrane is a thin solid structure that flexes in response to the change in air pressure caused by sound waves.