Search found 44 matches

by mwm
Wed Aug 31, 2016 2:18 am
Forum: FG085
Topic: PWM offset voltage?
Replies: 2
Views: 7587

Re: PWM offset voltage?

I started by looking at the manual. Note that we're talking about the two PWM modes here, not either CW or sweep mode. In the PWM modes, as in the CW and sweep modes, just pressing the AMP button will let you change the amplitude, just like it does in the CW and sweep modes. This is documented in th...
by mwm
Tue Aug 30, 2016 3:57 am
Forum: FG085
Topic: PWM offset voltage?
Replies: 2
Views: 7587

PWM offset voltage?

As noted elsewhere, I'm trying to use the FG085 as a servo testing tool. It actually works very well - or at least has a great set of features for that. It will do everything a high end servo tester will do, and more, for not a lot more money. However, I have a problem with a winch servo, which rota...
by mwm
Mon Aug 29, 2016 8:05 am
Forum: FG085
Topic: Problems with my FG085
Replies: 9
Views: 15564

Re: Problems with my FG085

I'm a bit leery of testing this, as I think it may have fried a USB hub. Maybe not, it was new and could have been a crib death. But that level of soldering is beyond my skills, so it may not matter. Any chance there's another way to test this? Checking the USB lines in an oscilloscope doesn't show ...
by mwm
Fri Aug 26, 2016 8:24 pm
Forum: DSO 112 & 112A (Coral)
Topic: DSO112A serial interface docs?
Replies: 31
Views: 50424

Re: DSO112A serial interface docs?

Any news on this? I can't really provide a pull request for the driver if there is no released software that works with it.
by mwm
Wed Aug 24, 2016 5:32 am
Forum: DSO 062
Topic: 062 LCD not lighting.
Replies: 2
Views: 35600

Re: 062 LCD not lighting.

Correct, the backlight doesn't come on. I confirmed the voltages on pins 19 and 20, and checked for open traces from them. Everything seems fine. This LCD module has always struck me as suspect, as it's missing the markings the assembly instructions refer to. Any chance of getting a replacement for ...
by mwm
Tue Aug 23, 2016 3:42 pm
Forum: FG085
Topic: Problems with my FG085
Replies: 9
Views: 15564

Re: Problems with my FG085

I hooked up a bench PS for the servo, and yeah - it's drawing 5 to 40+ mAmps under normal use, but spiking to ~120 when it stalls. I've ordered some voltage regulators; the comment about "may need it" made me think this would work. Any chance on getting test point values for the USB issue?...
by mwm
Fri Aug 19, 2016 12:43 pm
Forum: FG085
Topic: Problems with my FG085
Replies: 9
Views: 15564

Re: Problems with my FG085

Not driving a motor power se, just a servo. The 50mA provided by an Arduino pwm pin works fine for most testing, though stalling one could be an issue. But you normally don't check that with a servo tester. Can I get that much power, or do I need to get an alternative source?
by mwm
Fri Aug 19, 2016 1:05 am
Forum: FG085
Topic: Problems with my FG085
Replies: 9
Views: 15564

Re: Problems with my FG085

Well, if I can't use the user-generated waveform, maybe I ought to go back to the new firmware with better accuracy but breaks user-uploaded waveforms? Or have I misunderstood that? Clearly, something is shorted to the USB connector. If I plug the thing in with the FG085 turned off, my system sees t...
by mwm
Fri Aug 19, 2016 12:23 am
Forum: DSO 062
Topic: 062 LCD not lighting.
Replies: 2
Views: 35600

062 LCD not lighting.

This is the one I posted pictures of in the "Counterfeit 062" thread. The voltages are: D3: 10.3 D7: 0.3 *** Q1 Left: 0.05 Q1 Top: 9.47 Q1 Bot: 9.51 C17: 0 **** Q2 Top: 0 **** Q2 Bot: 9.5 **** U2: 4.3 **** U1: 8.25 ***** C25: 0.6 C22: 2.6 TP1(?): 2.71 TP3:2.91 **** TP4: 9.49 TP5: 5.02 TP6:...
by mwm
Thu Aug 18, 2016 5:24 am
Forum: DSO 062
Topic: Counterfeit 062?
Replies: 4
Views: 9771

Re: Counterfeit 062?

In that case, I think I have a dead lcd module. It doesn't light up at all. I'll post voltages tomorrow, but most of them seemed ok, though many were 1 volt higher than listed, which I assume is because I use a 10 volt ps. But for now, which side should the 20 pin header be attached to? The assembly...