Tronic's AMC motor motion-controller with pwm/servo output

Others have done it, so it does support it. If you ask me, it is absolutely pointless to use it because the firmware is the same, you gain no advantage. And it costs about 3x the At8535.

There is a point to it. The 644 supports higher chip freq. of 20MHz, and it makes it more stable when using 22.1184 and 24MHz for overclocking. I use it and have programmed and used the AMC at both freq. Use the proper crystal caps as advised by the manufacturer! The AMC is a superb device and has been working like clockwork for 1-1/2 years as per its design, including during testing of other projects where there were some damages caused (not to the AMC). If you are having issues with it, then it is your execution of build or perhaps faulty device(s), or you are trying to modify it...good luck.

And use the appropriate firmware developed by Thanos, which you will find on this forum.

I did not find it to cost 3X more, only a 25% premium.

R-eng

hello!

I want to build this board with exactly the same components but change the form, which is to fit in a box that I built.

any difference between the LM2940 and LM7805? I've seen both datasheet and not find any.

thanks
Rappa

Can anyone answer this post
tronic-s-amc-motor-motion-controller-with-pwm-servo-output-t559-860.html#p21124

Last time I checked prices in Hungary, the Atmega8535 cost about $2, the Atmega644 costs $7.
Newark sells the At8535 for $5 and the At644 for $10. Your supplier is either selling the 644 cheap, or the 8535 above price. I guess it depends on where you buy it.

I agree the 644 is more stable at 20MHz, but on the other hand I highly doubt anyone can notice a difference between 14MHz and 20MHz firmwares as long as the PWM frequency and baudrate remains the same.. We are talking about milli and micro seconds here for execution time.

pathetic, have you tried reversing the wires for your motors? When both direction LED's are on, it seems like the controller is trying to drive in both directions very fast. This would cause the same effects of heating as you described.

A benefit to the higher frequencies are quieter running motors.

@ rappa, LM2940 is a low dropout regulator.

R-eng

You are right, and that's why I said as long as the PWM frequency remains the same. It is independent of the clock frequency and can be set to whatever number below the maximum.

With 14MHz clock and 8bit PWM resolution the maximum PWM frequency is 54.7kHz
9bit resolution: 27.3kHz
20MHz clock, 10bit resolution: 19.5kHz

Speaking it practical terms, 8bit PWM resolution is smooth enough. 128 speed steps in both directions should satisfy everyone. To make the critiques happy, lets go with 9bits, 255 steps in both directions.

A 27kHz PWM signal is inaudible for most, and won't be a limiting factor in an H-Bridge setup. Most H-Bridges use lower frequencies, below 1kHz to reduce switching losses and heat.

hello!

R-eng can i put the lm7805 instead of lm2940?

thanks
Rappa

You can use the lm7805 no problems. Just make sure you have at least 7V going into the regulator. An alternative would be to use a USB port or a regulated 5V line from a computer as a supply, without the lm7805.

Absolutely, just as Frakk explains. Although I would highly recommend a min. 9v DC adapter just in case it falls short on specs.

R-eng

I have 18v, then i don t have problems!
Already did the board, is very good.

thanks!
Rappa

I wouldn't use 18V power supply. Your regulator might get really hot. A quick calculation with a 100mA current gives me 1.3W power dissipated in the regulator. With only 50mA, you will get 0.65W.

but I want the same energy source for engines and electronics ..
the regulator will be hot but I have a good cooling

Hi thano !

Can you tell me the differences between ATMEGA644P20PU and Atmega644-20PI ?
I have bought ATMEGA644P20PU last year and would use it!!

regards Stefano!

I'm not thano, but I'll answer.

PU is the new RoHS compliant chip using lead free manufacturing, PI is the old leaded version. Atmega644P and Atmega644 are a little bit different in architecture. You need a newer version of ponyprog to program the P version. Search this thread.

@tetesim
Go ahead and use the PU20; That is what I use and no problems with PonyProg (2.07c beta).

R-eng

thanks R-eng
Now I will open my controller and will change the micro. I try to program it with 2.07c beta!!

regards Stefano

Hi Tronic thanks for your awesome instructions. Ive just started back on this project and made the perfect PCB board via the light sensitive boards. (following your instrucitons making one out of a scanner)

I just need to know. (After stuffing it up myself first time around doing it this way) Why did you show a picture of an inverted PCB board diagram and then show a picture an uninverted PCB diagram on the scanner?
as it needs to be inverted right?

hello!

stay here what i go to do

thanks
Rappa

Rappa, excelent work!!!
you took all the unnecessary parts that are useless!!! like 8 Pots, servo (never working), programmer, etc

Board is very small!!!