Re: 8 Battery Lead Acid Slave Board
Posted: Mon Mar 21, 2011 12:41 pm
SERIAL COMMS:
Had a lot of trouble over the weekend getting my master and slave boards to communicate.
Seems the main trouble is that the built in pull-up resistor on the Avago fibre receiver is too strong (1K) for the wimpy parallel opto to overcome so I've had to do a little stanley knife PCB adjustment and bung in a couple of wire links. It's a wee bit annoying having to modify my brand new PCBs but not the end of the world.
I wish I had made the thermal breaks round the pads on the ground plane a little more generous too as it is really hard to solder/desolder components that attach to the ground plane. I suppose it's all a learning curve I still like Gregs surface mount idea, that's a definite for the future.
Got most of the display routine functional now. I decided to draw most of the screen at the start of the program and just use the main display routine to change numbers on the screen, this means less serial comms and more speed.
Derek
Had a lot of trouble over the weekend getting my master and slave boards to communicate.
Seems the main trouble is that the built in pull-up resistor on the Avago fibre receiver is too strong (1K) for the wimpy parallel opto to overcome so I've had to do a little stanley knife PCB adjustment and bung in a couple of wire links. It's a wee bit annoying having to modify my brand new PCBs but not the end of the world.
I wish I had made the thermal breaks round the pads on the ground plane a little more generous too as it is really hard to solder/desolder components that attach to the ground plane. I suppose it's all a learning curve I still like Gregs surface mount idea, that's a definite for the future.
Got most of the display routine functional now. I decided to draw most of the screen at the start of the program and just use the main display routine to change numbers on the screen, this means less serial comms and more speed.
Derek