How to build a 21st century protection board

Jump to Latest
#802
As you know I am not a fan of Arduino. I can not see why you would have an issue at the H/W level. The program that Valery sent me, is structured to run in a continuous loop, so adding code to initiate ADC conversions, checking for conversion complete/done, reading the conversion data should be well within the capabilities of the processor.
I guess it depends on what devices you are using to measure these parameters!
 
#804
unipolar, so config and then start the conversion cycle, monitor conversion done, read out the data.
What's the prob? Atmel should have lots of examples, written in C or asm.
Well I am curious, pitchfork pre-amp, orcad progress? just send me an email

cheers
 
#806
Temp Sensors

@jwilhelm

Something I have done a little research on. I was going to use a DS18B20, but doesn't go pass 125 C (but then I don't want a heatsink going pass it either)🙁, but cheap and easy to use. I found this LM73, which does go to 150 C using I2C, instead of 1 wire like DS18B20. Just a thought.

MI
 
Last edited:
#807
MadInventor said:
@jwilhelm

Something I have done a little research on. I was going to use a DS18B20, but doesn't go pass 125 C (but then I don't want a heatsink going pass it either)🙁, but cheap and easy to use. I found this LM73, which does go to 150 C using I2C, instead of 1 wire like DS18B20. Just a thought.

MI
Click to expand...

I2C sounds neat. I'll have to see if I can find matching current sensors.
 
#810
jwilhelm said:
I'm kicking around the idea of bringing all data from the amps in via i2c. I'm not sure what that would involve code wise but a i2c ribbon cable daisy chained around an amp would definitely simplify wiring.
Click to expand...


Well you will need something like this ADS1000 to convert all analog to I2C. There probably are quite a few pre-built volt to I2C modules. If using atmel 328P, pins 27 and 28 for SDA/SCL. There are a lot of resources for the atmel MCU, quite a few for I2C(wire library). You can use address 8-127. Try not to use them all.😉 Would be something if a group designed a universal amp control platform....huumm😎

MI
 
#811
MadInventor said:
Well you will need something like this ADS1000 to convert all analog to I2C. There probably are quite a few pre-built volt to I2C modules. If using atmel 328P, pins 27 and 28 for SDA/SCL. There are a lot of resources for the atmel MCU, quite a few for I2C(wire library). You can use address 8-127. Try not to use them all.😉 Would be something if a group designed a universal amp control platform....huumm😎

MI
Click to expand...

What I'm trying to design is a universal amp control. DC output protection would be right at the speaker binding posts so all the extra internal speaker wire would be eliminated. Current sensing and temperature sensing could be on a small remote board screwed to each heat sink. Rail shut down can be done by replacing rail fuse holders with a small daughter board. A small LCD could be added to the front panel of the amp easily if someone wanted too, but that's not something I'm really interested in. The hardware is easy for me to botch together, but I'm terrible with writing software. I've never had the time to learn enough about it.
 
#812
Don't sell yourself short, with all the arduino resources out there. I only started programming atmel late last year, but yes I taught myself C about twenty years ago. Here is a small snippet to start up a LCD display from my home monitor project:

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C mDisplay(0x27, 20, 4); //define lcd display I2C addr 0x27, 20 columns, 4 lines

Wire.begin(); //start I2C

mDisplay.init();
delay(100);
mDisplay.backlight();
mDisplay.noAutoscroll();
mDisplay.clear();
mDisplay.display();
delay(400);
Click to expand...

Not a lot of code, thanks to all the libraries available. Thanks to you, yes you 😉 I've started my own MCU design for amp control. I bought 10 328P, I now need to use them somewhere. I will use one for my preamp design, for mp3 playback and LCD display. So now with the LM73 or something else and optocouplers and other h/w interfaces, off I go on another project. If you need some help, let me know.

MI
 
Last edited:
#814
Hi,

MadInventor said:
Don't sell yourself short, with all the arduino resources out there.
Click to expand...

Exactly. There's no need to limit a sensing function to a single connection type, let alone a single device. 😉

With all the resources out there, it would be possible to fit any sensor to the microcontroller.

Would make a heck of a group project, haven't had the time to PM Valery back yet, though... 🙁

jwilhelm said:
One problem I'm seeing with these smaller i2c devices is the lack of address selection. I've looked at a few devices that have the same pre-configured addresses.
Click to expand...

There are multiple ways to deal with this.
The easiest usually is to simply choose devices with different addresses. 🙂
Another one is that some manufacturers offer variants of the same devices with different addresses.
Finally, there are ways to support multiple I2C busses on the same microcontroller.

Cheers,
Sebastian.
 
#815
jwilhelm said:
One problem I'm seeing with these smaller i2c devices is the lack of address selection. I've looked at a few devices that have the same pre-configured addresses.
Click to expand...

The problem is they use packages with few leads. That's why a SOIC package has more address bits. I agree with Sebastian, I would design using all interfaces as an option, one wire, I2C(TWI), SPI, even the serial port(s). The distance issue is not a concern in a chassis, with shielded cables. However, I do not want an LCD on my amps 😱, but a diagnostic port on the back to take some readings with external monitor would be 😎

MI
 
#816
Most 8 port expanders have more addresses to choose from. They don't take that much space in SOIC. I'd prefer to stay with one interface to make it easier for software challenge people like myself. Those ADS1000s are available in two preconfigured addresses. I just need to find a couple I2C temp sensors with different addresses and I'm all set for a stereo amp. I've got the next rev of control board 90% layed out. It has all the standard connections plus an I2C port, USB and FTDI serial adapter cable port.

We've talked about data-logging quite a few times already. I think it would be cool to have the amp networked and accessible through a web browser. I might add necessary connections for a Wiznet network connection to go along with the USB port as connections for LCD. This would make it useful for a lot of different things besides an amp control.
 
#819
My new version of the control board is layed out. Next are the satellite boards.
 

Attachments

  • Amp Control 4 SMD.PNG
    Amp Control 4 SMD.PNG
    114.7 KB · Views: 294
You must log in or register to reply here.
Top Bottom