Board with 8 DAC's

Hi,

I am new to Arduino... but I've been doing a lot of reading to see if some sort of MCU board has the capabilities I need. I need 2 MCU's: one that has 8 analog inputs (ADC's) of 10-bit resolution or higher (12 bit preferred) that are polled frequently (50+ times per second) and the values are transmitted over RS-232 to another MCU which has access to 8 10-bit or higher DAC's. The board constantly updates the DAC's with the new values as they are received.

I haven't found much hardware with DAC's at all, but I did read about some Xmega chips that contain 4 10-bit DAC's on them, and articles mentioning I/O expanding products that might be able to add DAC's over an SPI bus... but none of it has been very clear to me. If anyone has a suggestion as to what hardware could do this I would really appreciate it. The Analog output signals could either be 0-5v or +/-10v.

The application is pretty simple... I have several input devices for some robotics equipment that use analog signals. I would like to locate these devices remotely from the equipment and transmit the signals wirelessly over one communications channel, probably a wireless rs-232 converter.

Thanks for any help.

Aaron

Hi Aaron,

Sounds workable. Data rate of something like 2x8x8x50=6400 bytes/second x 10 = 64,000 baud rate. maybe need rs485 depending on distance. May need Uart with FiFo working??

Look at BU2505FV for example.

Do some searching at http://www.datasheets.com (sign up, free).. search "description" "10 bit dac". etc...

Terry, could you explain your arithmetic there, please? I get 50 (readings) * 16 bits * 8 (devices) = 6400 bits per second. Even with start/stop bits, I get only 8000 bits per second.

Me?? Math????

Hmm, OK let's try that problem again, slowly.

50 readings /s * 2 bytes per reading * 8 devices = 800 bytes / s .

Like You said, about 8000 bits/s second with 1 start, 1 stop, no parity.

Sorry.. ! Bits, Bytes, Whatever :D

An UNO has only 6 ADC channels that are multiplexed by just 1 ADC, so maybe you should use a Mega it has 16 DC channels. but I think they are multiplexed too (don't own a mega).

Have you checked - http://shieldlist.org - yet for ADC/DAC shields?

Try analog.com They have octal serial interface DACs. Easy to use. Mount one on a generic shield board to go out to your devices.