Using multiple A/D channels on the ADuC841 microcontroller

[uzykc]

Please, does anyone know a method of reading samples via multiple channels simultaneously on the ADuC841 microcontroller? Thanks

 

[rajtech]

Re: Using multiple A/D channels on the ADuC841 microcontroll

i will check the datasheet

 

[FvM]

I assume, that you actually mean simultaneous sampling, and that you know about the basic ADuC841 specification,
e.g. ADC througput. In this case, external S/H stages are a solution. You didn't tell a specification, so I simply suggest: design
a suitable S/H circuit or use available IC, e.g. Analog SMP04 quad S/H.

 

[uzykc]

Re: Using multiple A/D channels on the ADuC841 microcontroll

Thanks for your responses. But can i use the Direct memory access mode (DMA) for this?

 

[FvM]

Unfortunately, you didn't tell your exact problem.

 

[uzykc]

Re: Using multiple A/D channels on the ADuC841 microcontroll

Ok. I am trying to sample 2 signals from a Position Sensitive Device (PSD) which has to outputs into the ADuC841 uC. So far, i've been able to sample through only one channel at a time because the uC's ADC stores the sample in one address ADCDATAH, ADCDATAL (any configured channel with store it's sample in that address) this is becos there's an internal 8 to 1 MUX connected to the ADC. I'll will include the data sheet. Please, your help is highly appreciated. Thanks.

 

[FvM]

I know the datasheet, thus I mentioned, if you actually mean simultaneous sampling, you would need an external
sample and hold circuit. Now you have confirmed, that you do need it. That's it.

As an additional point, if you intend to take multiple (two channel) samples trough DMA, you should try to setup a timer
output, that controls the S/H circuit.