Hi,

A while ago I asked for help with searching a Microcontroller. I'm a little bit more familiar with the wonderfull Microcontroller world by now, but I still can't find a board that suits my needs.

I ordened an Arduino Mega. Great stuff and nice (free) development tool, but the main problem is that none of their boards have true Analog Outputs, only PWM outputs. I could connect a 'SPI -> DAC' board. But a nicer solution would probably be a Microcontroller board that has the DAC's directly connected. However, I can't find one. Lots of A/D, but no D/A. What I need:

- A complete "ready-to-use" board. I'm not able to solder loose components together myself
- 16 bit processor
- 2 Analog outputs (0..5 Volt or 0..10 Volt) with a high settle time (< 0.5 ms)
- 2 Analog inputs. Again with a very high reading ability: Each of them should be read at least 2000 times a second.
- 4 interrupts (on pulse)
- 4 digital in, 2 digital out

Does someone know such a board? Or how do you guys search? I have seen 15 billion chips and boards on dozens of websites, but most of them are just chips or starter-kit boards (without D/A). Maybe I'm looking wrong though.

Regards
Rick

 

https://www.silabs.com/products/mcu/Pages/C8051F060DK.aspx

 

That looks really nice, the complete package! Can you help me through the specs though, I'm not familiar with all the hardware-talk so I don't really know what I'm reading:

- What board / chip does that package exactly include? A "C8051F020TB"? Ifso,

- Analog inputs
Several tables in the PDF documents tell all kinds of things. For example: "ADC1: 16-bit, 2-ch, 1 Msps" and "ADC2: 10-bit, 8-ch, 200 Ksps". I guess it means 2 16-bit inputs, 8 10-bit inputs. But how fast is Ksps/Mspsp?

- Analog outputs
Output settling time = 10 us. This is the time required an output is "stabilized"? Ifso, that would be more than quick enough.

- Interrupts
5 16 bit timers. That means I could use 1 of them to quickly keep reading the analog inputs? (~4000 times a second for example). How about the interrupts that can be triggered in pulse? I need 4 of them, but I can't find any info about that.

[edit]
- The development software
I see you can download Silicon Labs IDE, but another manual says the software included a limited version of Keil (4kb ROM size limit). Can I do without Keil? And the 4kb limit... probably my program is small (read analog outputs in timed interrupt, measure peaks, send them to the analog output + some pulses, that's it).

Sorry for the stupid questions, but I'm a rookie when it comes to hardware so forgive me! Just want to make sure I'm buying the right thing.

Thanks!
Rick

 

The board has the C8051F060 device + 128 Kb SRAM

It has 3 ADCs, the 16-bit each have a dedicated channel and the 10-bit has 8 channels multiplexed. You wanted 2 ksps and this devices exceeds that.

It should meet your settling requirement

It has a window-detect on the analog input that can generate an interrupt or you can have a adc conversion complete generate an interrupt.

There is a SDCC compiler you can use for 8051 or the 4kb limited Keil compiler might work for you.

 

Spek

You indicated in your original post that you were looking for a 16-pit processsor. I believe you will find that the C8051F060 is only an 8-bit processor.

I assume you are OK with that.

hgmjr

 

Hi Rick,

I am about to introduce an Arduino compatible board with a 4 channel, 8 bits per channel
DAC and a battery backed-up RTC. The board is a 3.3V design with an 8-bit uC (ATmega168 or ATmega328). The DAC goes to apx 2.5V (2 * Vref).
Specifications are in the NB1A section at http://tinyurl.com/pg334s
It is a kit but I do build up some boards. Feel free to contact me off-list.

(* jcl *)

 

8 bits... Not really a problem I guess. There is always a workaround in case I would need bigger numbers.

I'll wait though. Instead of using analog data I can also use the UART to pass data. In that case I can just sample an array of values and send it on relative low speed. In that case I can do the job with our current Arduino. Nevertheless, a MC with analog outputs can still become usefull in the nearby future, so I'll keep this board in mind, and also yours John. I like the user-friendly environment and forums at Arduino so one of their boards with analog output is certainly a plus.

Thanks for helping everyone!

 

When it comes to analog output, you can use an R2R ladder network and an opamp to create your own D/A. Another approach that is used is a PWM signal that is lowpass filtered. The beauty of the PWM approach is that it consumes only one output.

hgmjr

 

fully featured with in-built ADC, LCD, 7-segments, ISP, 5 & 12V regulators, Dip switches, Relays, Stepper motor Control, usb, serial & parallel ports....

 

fully featured with in-built ADC, LCD, 7-segments, ISP, 5 & 12V regulators, Dip switches, Relays, Stepper motor Control, usb, serial & parallel ports

Is there a datasheet or userguide? Does it have a DAC? Does the AT89S52 really have built-in ADC?