Juma Clone Amp Firmware - Boot Loader + Latest Firmware update using combined .hex file - Detailed Steps

[Mukundan N]

/*** Note - These steps are for Windows 11  ****/

1) Download  MPLAB X IDE setup file ( v6.2.0 worked for me with the pickit I have )

2) Select only MPLAB IPE  when the installer asks

3) After installation , connect pickit and install missing dependent libraries  if any.

4) Open up the Amp , and connect a 6 pin JST connector to J19

it is very difficult to remove the LCD screen as it is directly soldered to the board. So I have soldered this pin in a 45 degree angle :-)

5) Before connecting the other end to Pickit , do some settings in MPLAB IPE as shown below

6) Now try to connect other end of 6 pin connector to Pickit ( make sure the pin numbers are properly aligned. )  , and choose the below parameters

7) Connect to pickit and see if it able to find the pic from the Amp. 

8) Connect 12 v to Amp , switch power ON in the Amp and hold the power button. Now try to click on the "Read" button in MPLAB IPE. If IPE reads the pic , then export the read .hex as a backup 

9) If "Read" is success , then browse and select "Merged_Juma_PA100.hex" ( attached as .hex.txt   , please rename to .hex ) in IPE

10) As we did for "Read" , power on and hold the button.

11) Click on "Program" , make sure that  the power button is pressed till the write completes.

This should show the log as below :

Connecting to MPLAB PICkit 3...

Currently loaded firmware on PICkit 3
Firmware Suite Version.....01.56.09
Firmware type..............dsPIC30F
Target voltage detected
Target device dsPIC30F6014A found.
Device Revision ID = 1041


Device Erased...

Programming...

The following memory area(s) will be programmed:
program memory: start address = 0x0, end address = 0x17fff
configuration memory
EEData memory
Programming/Verify complete
2026-06-08 16:56:51 +0530 - Programming complete
***   Release From Reset mode is enabled   ***

12) Once after successful "Program" , press "Disconnect" in tool and remove the Pickit connections to the 6 pin connector.

13) Power off and on the Amp , that should now be with updated firmware.

14) You may do the calibration as per the standard documentation.

Many thanks,

Mukundan ( VU3KNB / M6KNB )

[Ken Johnson]

Thank you for the write-up. I have a Juma Clone that is not modified. I works well except for the Over Current trips occasionally.  If I do this upgrade, what are the benefits? I did buy a Pickit awhile ago but I wanted to do more research before I made the change. 

Thank you,

WB8VTW

[Mukundan N]

Hi Ken,

My ultimate aim is to remote control the amp using "Juma remote control" tool in my home network ( probably outside too using VPN or so ) 

Unfortunately the clone arrive from CN , is with an older firmware , that do not support remote control. 

That was the main reason for me to update this clone with latest firmware. 

 I still need one TRS (3.5mm) to RS232 converter to get the amp connected to a pc or a Pi , I am in the phase of sourcing that.

May be I shall update my GitHub repo with those details too.

https://github.com/vu3knb/Clone_of_Juma_PA150D

73

Mukundan

[Ken Johnson]

Thank you. I understand that SWR and CURRENT trips are addressed in the update. Remote control will be nice to have to reset the trips. I installed the software and it asked for the Microchip device. I chose dsPIC DSCs.

[Mukundan N]

yes , 2nd option "dsPIC DSC and 16 bit PIC 24" needs to be selected while installing MPLAB IPE. Thanks for pointing this out , I will update this in GitHub.

[Ken Johnson]

I did the upgrade per your writeup. At first I downloaded version 6.3 of the MPLAB X IDE. I figured it was the latest so it had to be the best? Well it did not find my Microchip Pickit3. I fumbled and scratched my head and then I decided to download Ver 6.2 as seen in your instructions. Viola, it found the Pickit3. I continued with your instructions and I have an upgraded RS-928. I am not sure why Ver6.3 took me off in the woods but 6.2 worked fine. 

Thank you

WB8VTW

[Mukundan N]

Great to know that you have upgraded Juma clone :-) 

I also homebrewed one interface using A TRS 3.5mm pin , "Serial Port Mini RS232 to TTL Converter Adaptor Module Board MAX3232" ,  and "FTDI FT232 FT232RL USB to UART TTL Serial Adapter Module"

This interface is correctly working as expected and have used  Charlie KB8CR's  NodeRed flow in a Pi to control my PA over home network. 

 

[Ken Johnson]

Thank you for your help. 

I noticed a new behavior that I did not notice before the upgrade. Calude wrote some code for the I/O board and tuner operation. He created another amplifier keying line that is not active when CTRL-TUNE is used. This prevents the amplifier from keying when the tuner is doing its thing. With the RS-928 not keyed but in the operate mode, it throws SWR alarms. I did not notice this behavior before the upgrade. I may have missed it but I do not recall it behaving this way. 

I am not sure that there is a way to supress SWR alarms when the amplifier is in the operate mode but not keyed? This is not a real PITA when the amplifier is nearby but remote it creates a real problem. 

WB8VTW

[Mukundan N]

Hello , I don't use IO board , so can't comment on this.