Firmware mod for GWInstek GPP series lab bench power supply

[Pr Utser]

@Cavhat,

Thanks for reporting this issue. While trying to reproduce I found that the web server interferes with the measurement readouts. Luckily there is an easy fix for it. The bug will be fixed in mod release 1v03 which I will post next.

[Pr Utser]

GPP mod version 1v03
New features:
• None
Bug fixes:
• Fixed measurement readout interference from web server (applicable for units with LAN option). Special thanks go to member Cavhat for reporting this issue.

https://sourceforge.net/projects/gpp-mod/files/release/gpp_mod_1v03.zip/download

SHA256                                                                    Size  Name
---------------------------------------------------------------- -------------  ------------
BD7BC2C4DA56360A50968F05E3B67AE65C4EA10327C938F29843C5FD8E0A7658      67705459  gpp_mod_1v03.zip

97752D0AEFAEB1F48A04F3AA54F511B6556FA7C8D8574528BA32292A8F58DC73          1217  gpp_mod.cmd
BB2825729841DB31ECB218EB5194DDAFACE654D4429AC6EA0BD69FA5B8BB43BF      67509643  gpp_mod.exe
51979F9122A0E9F0F10AE4A845F7BD90B1AFA0282871EA2930ED57813EBFC9B6          8824  gpp_mod.hex
BAFD515E11A7F2787C581C0C68E362084A6E175A9B199364B285DB8F344EA66A        636517  gpp_mod.pdf
1B93DC917E7BF75C07F4A1E83ADF46826B2A787EE7451C6B40337678047C78BC         14527  gpp_mod.py
F99B389E30A2576D7A1591D1EA755BBDCD16DDB9B9BFFE37B273C4BBE16453D9          5003  gpp_mod_template.json

[Wade2019]

@Pr Utser

Hello, I have a GPP-1326, this firmware can be directly upgraded to GPP-1326？？？

[Pr Utser]

Hi @Wade2019,

I have not tested the mod on a GPP-1326 myself but I see no reason why it would not work.
The mod has been developed to support all GPP-x32x models.
Personally I tested it on a GPP-4323 with LAN option but without GPIB option.

Maybe others could comment on what they are using.

[pcee]

@Pr Utser, thank you for this amazing mod!

One question about calibration arising from the instructions:

Step 5.j says to repeat measurements with a 20V setpoint voltage.  That's suitable for CH1 and CH2, but what about CH3 and CH4?

[Pr Utser]

Good point @pcee.
You can choose a stable voltage just below the max output voltage of the channel. It will be fine as long as cal0 and cal1 have different voltage settings and the actual value is taken over in the voltage field of the cal section in the json file. The larger the difference between the cal0 and cal1 voltages, the better.

[mawyatt]

GPP mod version 1v02
New features:
• Configurable window size of first stage measurement filter (moving average filter)
• Added second stage measurement filter with configurable window size and reset threshold
• Configurable display update interval
• Added gpp_mod.cmd batch script for starting gpp_mod directly from Windows Explorer

https://sourceforge.net/projects/gpp-mod/files/release/gpp_mod_1v02.zip/download


SHA256                                                                    Size  Name
---------------------------------------------------------------- -------------  ------------
6911FEC2138C8BE5AD48123D9DF2B65C981E5B2EE8A4419855238D2B435E99E6      67718030  gpp_mod_1v02.zip

97752D0AEFAEB1F48A04F3AA54F511B6556FA7C8D8574528BA32292A8F58DC73          1217  gpp_mod.cmd
79B6442CB5CEEF5FA310513FEE55CB520F7654F6914D094CDE08BDDB7947ABFF      67509643  gpp_mod.exe
3F0BAE540E9E977C8B69D36091ADB7FDC577A2D104CF4EA0AE4D879FF793BC0A          8713  gpp_mod.hex
4B7E81EB97198624AE86CDD41FFB24C914B04469F7E34A320E9B9DBD96F6A2B2        649049  gpp_mod.pdf
1B93DC917E7BF75C07F4A1E83ADF46826B2A787EE7451C6B40337678047C78BC         14527  gpp_mod.py
F99B389E30A2576D7A1591D1EA755BBDCD16DDB9B9BFFE37B273C4BBE16453D9          5003  gpp_mod_template.json

Thank you for the additional features for the GPP-4323, having the ability to calibrate such is quite useful indeed 

A question on how the two Moving Average Measurement Filter works, specifically how the Reset Threshold behaves?

Is this in Absolute Value Volts (Amps) wrt the Output of the 1st Moving Average Filter?

Best,

[Pr Utser]

A question on how the two Moving Average Measurement Filter works, specifically how the Reset Threshold behaves?
Is this in Absolute Value Volts (Amps) wrt the Output of the 1st Moving Average Filter?

Indeed,  the resetThreshold value is compared against |stage2FilterIn - stage2FilterOut|.
You can also state |stage1FilterOut - stage2FilterIn|, because the output of the first stage filter is the input of the second stage filter.

[Solacity]

As the recent owner of a GPP-4323 I would first like to thank Prutser (goede naam!) for the firmware improvements! Much appreciated!

I also have a request, with absolutely no idea if this is easy to do or not:
The calibration settings make the GPP metering (much) more accurate, but they do not improve the value that is dialed in (say, "10.000 Volt" or "0.020 Amp") vs. what is actually coming out once the 'enable' button is pressed. Yes, you can immediately see from the measured values on the display what the actual is that is being produced, but it would be nice to align the requested vs. actual.

Mind you, it's not off by much. It's mainly in the lower ranges of mV and mA that it really would make a difference. For example, I was playing around with some LEDs this morning and dialed up a current limit of 20 mA. The actual is more around the 16 mA mark for me, on channel 1.

Maybe an extra parameter added to <channel1_voltageCal> and <channel1_currentCal> with something like voltageCalEntry:= { "set": <set_voltage>, “ref”: <ref_voltage>, “gpp”: <gpp_voltage> }, and currentCal:= {"set": <set_current>, “cal0”: <currentCal_subsection>, “cal1”: <currentCal_subsection> }.
So it would do linear interpolation to correct the set/dialed value towards the actual, and of course correct the metered to measured/calibrated.

As I said, no idea if that's easy to do within the firmware, but thought I'd ask.
Thanks!

-Rob-

[Pr Utser]

I also have a request, with absolutely no idea if this is easy to do or not:
The calibration settings make the GPP metering (much) more accurate, but they do not improve the value that is dialed in (say, "10.000 Volt" or "0.020 Amp") vs. what is actually coming out once the 'enable' button is pressed. Yes, you can immediately see from the measured values on the display what the actual is that is being produced, but it would be nice to align the requested vs. actual.

This should indeed not be too hard to implement. For the current setting this makes more sense to me than for the voltage setting. However, when implementing it does not matter much to do it for both current and voltage. Not sure though what the unit is of the setpoints that are sent to the channel MCU's. Most likely it is mV and 100uA which would provide sufficient calibration resolution of +/- 1 digit.

I don't know when (or if) I'll be working the mod again. But I'll definitely consider your request in case I make a new version. Another thing in mind is to limit the setpoint when OVP/OCP is enabled. With the original firmware, the output can overshoot the setpoint before OVP/OCP kicks in. Not nice when noticing a typo after entering a new setpoint.

[mikept]

Hi all,

Thank you for the great work, Prutser.

I would like to install the mod on a GPP-2323, mostly to improve the current readout and take care of the annoying beep, but I can only get the most current firmware from GW Insteak (GPPV126.BIN), which is not compatible with the mod. Can anyone share the older firmware file (GPPV122.BIN) with me?

Thank you!

[cte]

Hi all,

Thank you for the great work, Prutser.

I would like to install the mod on a GPP-2323, mostly to improve the current readout and take care of the annoying beep, but I can only get the most current firmware from GW Insteak (GPPV126.BIN), which is not compatible with the mod. Can anyone share the older firmware file (GPPV122.BIN) with me?

Thank you!

I've attached v1.22 firmware for GPP series multi-output DC power supplies.

[mikept]

I've attached v1.22 firmware for GPP series multi-output DC power supplies.

Many thanks, cte! I've already flashed the power supply and it's working great. 

[Wade2019]

Hi Pr Utser;

When I was testing the maximum power of GPP-1326, I found that the OTP protection was on. After analysis, I found that after flashing your latest firmware, even though the radiator was at 60 degrees, the fan did not start high speed to dissipate heat, causing the machine to be protected.

[Pr Utser]

Hi @Wade2019,

Is this in supply mode, load mode or either mode? Could you share more details about the test?
Did you also check the behavior of the original GWInstek version 1.22 firmware?

I just checked it on a GPP-4323 (modded v1.22 firmware) with channel 1 sourcing 49.75W into channel 2 as load. Within a few minutes, the fan RPM started slowly stepping up to what sounds like full speed.
So the fan RPM seems to be temperature controlled (closed loop control). There does not seem to be a feed forward based on actual power delivery/sink. I do not have the schematics of this supply so I am wondering if OTP is based on the temperature sensor of the control loop or a redundant one.

GWInstek does not provide any release notes with their firmware updates so I do not know what the fixes or improvements are.
The GWInstek website states that you need to update from prior to v1.16 to v1.16 first before any later update. Could be important, but the v1.16 is nowhere to be found on their website. My unit was already on a more recent version when I got it. I do not know what the consequences are if this intermediate step is skipped.

Best regards,
Prutser

[Hydron]

Attached a copy of 1.16 if anyone needs it.

Does anyone have any idea what was changed from 1.22 to the current 1.26? (Assuming not - as mentioned above they don't give any changelog )

[Wade2019]

Hi@ Utser;

I tested the power mode and ran it at 33V 6A, but did not test the load mode. I found that the power module had OTP protection, and I carefully observed that the fan was not running at high speed. My software was indeed upgraded to v1.16 and then upgraded to your modified version v1.22 firmware. The official website does not have version V1.16 firmware. I have downloaded version 1.16 from other locations of GW Instek. Version 1.16 is included in the attachment.

The test focuses on full power operation