Dead LV-168?

Support A-Star and Orangutan
1

I have an essentially new LV-168, which has been programmed only a few times (for the purpose of the RPM meter that I posted some time ago). I recently had time to pursue some new ideas, but in the first go-around using the Pololu programmer, programming seemed to start off correctly but failed somewhere in the process.

The unit is powered by a recently charged 3.6V NiMH pack and the board Vcc checks out at 5.00 V. There are no motors connected, nor any connections to the I/O lines.

The programmer knows that it should be talking to an ATmega168, but I can’t read the device fuses. I tried various ISP clock frequencies to no effect. I also tried unplugging the LCD display (which showed a line of grey rectangles) but this did not help.

I switched to the AVR-ISP mkII programmer, which depending on what you try, reports various problems such as SCK shorted to ground, wrong pullup on reset line, the ISP connector is the wrong way around, etc. However, both the Pololu and AVR-ISP programmers will properly program the earlier model Orangutan 01a (ATmega168 version).

After the failure I noticed that the blue power LED sometimes goes dark, for no obvious reason.
If power were interrupted somehow during programming, could the board be revived at the factory by parallel programming or some other procedure?

Could this be a case of infant mortality, or is there something else I should check?

Thanks for any advice that anyone can offer!

Cheers, Jim

2

Hi, Jim,

Sorry to hear about your board. Are you using our old programmer, with the CP2102? It sounds like the board has some kind of power issues, so we should probably take a look at it. If you send it back, we can fix it or send you a new one. (We generally can’t recover messed up AVRs, so we would have to replace the AVR if the rest of the board is in good enough shape to make it worth it.)

- Jan

3

Jan:

Thanks for your response and willingness to take a look. I used the old Orangutan programmer, as I don’t have the newer version, but problems are certainly there with the AVRISP mkII programmer as well. The mkII, incidentally, can be pretty flaky at times.

I mailed the LV-168 in question to you by first class post and hope that you can make something of it!

Jim

4

We replaced the AVR, and the unit seems to be working normally. We checked the power parts under the microscope and looked at various waveforms on an oscilloscope, and everything seemed normal, so we didn’t do anything else. So, I hope whatever power issues you had were from a bad battery connection or drawing too much current or something like that.

You should get the usual shipment confirmation after the package goes out later today.

- Jan