Humm... the TAS3251 is a I2C Slave only.
The uC to manage Power ON, OFF, DSP coeff loading shall be an I2C Master
Then, if we wand a more powerfull controller take the relay, it also has to be a Master. Main target is a Raspeberry Pi, and from my analysis, it appears that the RPi can't be a multi-master...
So it won't work "simply".
The board uC could "switch off" its I2C after loading the components, but there is still a risk that the RPi, if powered prior to the board would start to interact before that board uC swith off. Would not be OK.
I have to investigate this more...
JMF
The uC to manage Power ON, OFF, DSP coeff loading shall be an I2C Master
Then, if we wand a more powerfull controller take the relay, it also has to be a Master. Main target is a Raspeberry Pi, and from my analysis, it appears that the RPi can't be a multi-master...
So it won't work "simply".
The board uC could "switch off" its I2C after loading the components, but there is still a risk that the RPi, if powered prior to the board would start to interact before that board uC swith off. Would not be OK.
I have to investigate this more...
JMF
Attiny441 has a Slave only I2C
Attiny841 same.
But I still have to investigate a bit further the I2C master(s) question...
JMF
As you're experienced with STM32 ODE, why not usinq a cheap bluepill board ? a STM32F103C8 will easily do the job and can be programmed with CubeMX and STM32CubeIDE. You can use the board as is or on a motherboard as DimDim did on his generic dac front panel.
If size matter, there's a the new STM32G030J6 in 8 pin SO8 package and many F0, G0 and L0 in 20 pin packages.
Chris
If size matter, there's a the new STM32G030J6 in 8 pin SO8 package and many F0, G0 and L0 in 20 pin packages.
Chris
Hi, I "survived" to the STM32 IDE. But it has a quite steep learning curve. Being able to program the thing with the Arduino IDE would open possibilities to more people. However I see that there is a STM32duino thing for those. Will have a deeper look.
Would you have a link to the DimDim generic DAC front panel ?
JMF
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I have no clue about this stuff, but a quick search turned this up:
ATTiny USI I2C Introduction - a Powerful, Fast, and Convenient Communication Interface for Your ATTiny Projects!: 8 Steps
Hope it can provide some pointers at least.
Or if you find other sources for information I think it's nice to have the links to the material, may give others in similar situations a fighting chance.
ATTiny USI I2C Introduction - a Powerful, Fast, and Convenient Communication Interface for Your ATTiny Projects!: 8 Steps
Hope it can provide some pointers at least.
Or if you find other sources for information I think it's nice to have the links to the material, may give others in similar situations a fighting chance.
Bitbanging software I2C will do it i guess or USI. An advantage of I2C is, it can be scaled down with no problem, even at speeds of 500Hz. 
Or check this:
Technoblogy - Minimal Tiny I2C Routines
Or check this:
Technoblogy - Minimal Tiny I2C Routines
I switched from Arduino to STM32 because I wanted to have free control and usage on all the internal peripheral of the MCU, such as DMA, SAI, DAC, ADC, Timer, etc...No way I switch back to Arduino, but you're right I did invest some time learning CubeMX, Eclipse and the STM32 hardware at the register level.
ST provide many videos on their youtube channel, with mooc related to the IDE, the MCU families, etc.. great content wich wasn't available at the time a switch to STM32
Here's link to DimDim's thread : GB for ArDAM Lite bare PCBs
I may reconsider my idea about stm32: stm32f0 chips are very cheap, they are available as "basic parts" at JLCPCB (where I have the intention to gat the PCB ans part of the assembly done), they reauire very little BOM (to be digged further), I imagine they can have native I2C master feature. And maybe they can be programmed with Arduino.
More work tomorrow.
JMF
More work tomorrow.
JMF
To look if there would be some interest.
My intention is to have a set of 10 boards manufactured at JLCPCB with as many as possible components fitted. This would exclude "expensive components" like the TAS3251, coils, all through holes, connectors, headers... and some of the SMD.
I think that I would have 5-6 boards left. Would there be some interest if I was selling them about:
- Real cost rounded to the next 5€ (should be about 10 or 15€) + shipping to the person if booked now,
- Double manufacturing price + shipping to the person once tested and demonstrated as working.
This would be a board where about 70% of the components where already there, with some remaining SMD and Through Hole to be procured and soldered.
If interested, please let me know.
JMF
My intention is to have a set of 10 boards manufactured at JLCPCB with as many as possible components fitted. This would exclude "expensive components" like the TAS3251, coils, all through holes, connectors, headers... and some of the SMD.
I think that I would have 5-6 boards left. Would there be some interest if I was selling them about:
- Real cost rounded to the next 5€ (should be about 10 or 15€) + shipping to the person if booked now,
- Double manufacturing price + shipping to the person once tested and demonstrated as working.
This would be a board where about 70% of the components where already there, with some remaining SMD and Through Hole to be procured and soldered.
If interested, please let me know.
JMF
I think you'd have bigger interest if you offered a complete thing, most members are a bit uncertain about soldering SMD components and stuff with lots of pins.
It would probably be good to have a list of things you aim for as well, like how many points of eq per channel, which filters/slopes you can set up etc.
Personally, I would like to know if you can sort of "daisy chain" these things, like: connect toslink to one board, and it runs as master, another board is connected as slave using some simple flat cable with headers or the like. Both boards are configured through the same UI, and all available channels can be adjusted individually with PEQ and filters.
I guess it might be a bit hard to sell these boards for more than say 150$ each + shipping, so my suggestion is try and stay below that. People still have to get PSU's, connectors and enclosures +++ which add further cost.
Just my 3.5c
It would probably be good to have a list of things you aim for as well, like how many points of eq per channel, which filters/slopes you can set up etc.
Personally, I would like to know if you can sort of "daisy chain" these things, like: connect toslink to one board, and it runs as master, another board is connected as slave using some simple flat cable with headers or the like. Both boards are configured through the same UI, and all available channels can be adjusted individually with PEQ and filters.
I guess it might be a bit hard to sell these boards for more than say 150$ each + shipping, so my suggestion is try and stay below that. People still have to get PSU's, connectors and enclosures +++ which add further cost.
Just my 3.5c
You know, I don't do it for the money. If it had to pay just for my time, then it would cost much more than the limit you propose. There are very good alternatives like the hypex nCore or the 3e-audio offer. So it does not makes sense for to try to build a commercial product, with procurement, soldering, after sale.
However, it could be of interest for a Maker, with niche needs that would fit, interested with experimenting with the chip, but not with the TI EVM board
For me, the learning is the reward (and it is still not the end of the road).
JMF
Today, I tried to work about the different board possible use cases, with onboard uC or external controller. One of the main applications of the DSP+amp thing is for Multiway active speakers, where you replace analog filters with the DSP (this is my personal objective, for my LX-Minis).
I went back to TAS3251, TAS3251EVM, TAS5825 datasheets... and obviously there are strong conditions on the Power-On sequence of the DSP part and the Amp part. I had focused up to now on the Amp part, that could be solved (but not so easily) with a board uC.
It seems to happen that it could be the same for the DSP part, that would need to have the I2S clock applied to the board before init of the DSP stage. This is TBC (To Be Confirmed), I have a question on the E2E site about this.
As a consequence, if the DSP config can't be done before I2S clock is applied, this means that all the use cases have to ensure that the board front-end is up and running (including I2S clock) before the TAS3251 power ON sequence.
All the font ends I have in mind have the ability to provide the I2S and I2C and needed IO (Rpi, Nucleo dev board...). So finally, I don't identify a use case that would really benefit from the onboard uC (which I don't like so much as I have digged a lot of information this week about the AVR and stm32F0 uC)
Would you identify some use cases of interest where the I2S clock would be present at boards inputs during the pwer ON sequence, but that would still benefit from an onboard uC ?
JMF
I went back to TAS3251, TAS3251EVM, TAS5825 datasheets... and obviously there are strong conditions on the Power-On sequence of the DSP part and the Amp part. I had focused up to now on the Amp part, that could be solved (but not so easily) with a board uC.
It seems to happen that it could be the same for the DSP part, that would need to have the I2S clock applied to the board before init of the DSP stage. This is TBC (To Be Confirmed), I have a question on the E2E site about this.
As a consequence, if the DSP config can't be done before I2S clock is applied, this means that all the use cases have to ensure that the board front-end is up and running (including I2S clock) before the TAS3251 power ON sequence.
All the font ends I have in mind have the ability to provide the I2S and I2C and needed IO (Rpi, Nucleo dev board...). So finally, I don't identify a use case that would really benefit from the onboard uC (which I don't like so much as I have digged a lot of information this week about the AVR and stm32F0 uC)
Would you identify some use cases of interest where the I2S clock would be present at boards inputs during the pwer ON sequence, but that would still benefit from an onboard uC ?
JMF
Does the DSP support self-boot via internal/external Eeprom? If not, this is one use case where the board needs to get the DSP code loaded at power-on. I.e. standalone operation with I2S source.
Something like BT-Stream via I2S into 3251. (Which is my main application actually using CSRA64215 + ADAU1701/1401 + TPA3255.
The other thing would be a simple frontend for volume/mute/eq-switching.
Something like BT-Stream via I2S into 3251. (Which is my main application actually using CSRA64215 + ADAU1701/1401 + TPA3255.
The other thing would be a simple frontend for volume/mute/eq-switching.
The below link may be helpful for your project. googling for lxmini 4 channel with dsp.
4 Channel DSP Amplifier with ADAU1701 & TPA3251 | SCHMIBEN UNLIMITED
4 Channel DSP Amplifier with ADAU1701 & TPA3251 | SCHMIBEN UNLIMITED
