You are currently viewing S21RC SSPA Controller Hardware Rev 3.x

S21RC SSPA Controller Hardware Rev 3.x

[PCB, Schematic, and microcontroller codes released under MIT license by S21RC. You are free to use the material for personal/commercial use as it is or modify if needed as per the condition stated in the license], in simple term, software should contain the same copyright/license file and attribution. HMI display should have the “info” screen with all information and the Splash screen.

UPDATE: 28 March 2024
PCB 3.0.2B – all known missing ground fixed.
The project is now tested and in usable state.
All files are in Github: https://github.com/s21rc/SSPA-Controller-rev3

UPDATE: 22 JAN 2024
PCB REV 3.0.2 fixed missing ground and 2 short on i2c line.
CODE: (in progress.)
Function Block:

UPDATE 5 July 2023:
Rev3.0.1 BOM, CPL and Gerber uploaded.

UPDATE: During the test found some error and some improvement areas. New layout in progress.
Changes made:
1. CAT (CI-V) function added.
2. Pullup resistors added (error found during test – PCF8574 unable to drive ULN2803 without pullup)
3. External protection trigger IN is now routed through optocoupler.
4. BTS4141N replaced with TPS22810
5.

TEST RESULT:
1. Display function works ok
2. Setting save works ok.
3. Hardware protection for high input and swr tested ok.
4. Software protection works ok,
5. all temp sensor works ok.
6. Relay driver: Failed, need pullup resistors.
7. BIAS control Failed – BTS4141n might be fake.
8. All interrupt works ok.


After making the basic controller v1 which only had few peripherals and used through hole components and cheap Arduino Nano I decided to make another version with more options and future expandability. The Controller Rev2.0 was designed with Arduino Mega for the higher count of I/Os, but that never left the design table as I was hungry for more speed/power and expandability options. Born the Rev 3.0 utilizing Teensy 4.1 Microcontroller board which runs at a huge 600MHz speed (NXP iMXRT1062 chip with ARM Cortex M7 core).

Except the headers and few parts, all other components are SMD to save space. 1206 packages (cap, res, diode etc) has been used for easy home soldering.

Features:
1. 600MHz MCU
2. Highspeed comparator (LMV339) for monitoring high SWR/Power
3. Same PCB can be used for both high side switch and low side switch LPF boards (The final IC need to be selected as per your LPF type)
4. WiFi application with a ESP32 Wroom module (Optional)
5. Band Decoder (BCD and Voltage)
6. PTT input, PTT relay control.
7. 8 LPF channel for supporting future 4m.
8. Voltage and Current monitor.
9. Rotary band switch (optional)
10. Onboard CAN Bus controller for common PSU
11. 3 directional bridge/ SWR bridge input (Amp in, Amp out, LPF out)
12. Digital and 2nos NTC Temperature sensor options.
13. Protection Trigger out for external protection board
14. Board size (134x84mm) is same as Nextion 5″ display and can sit behind the display.
15. 2 25/31 KHz PWM out for Cooling fan.
16. OPT1 header has I2C, SPI and few I/O which can be used for more functionality or for a future daughter card (how about a 4×4 antenna switcher, or a sequencer, or….).
17. Can be used with 5/7/10 inch Nextion HMI display.

Software:
The display UI will be based on previous V2.0 UI with additional setup and features page for accommodating the new peripherals and options.
Or you can write your own code for this hardware.

Schematic:
Will be updated here.

BOM:

BOM for Rev 3.0.1


PCB Gerber:
Download LDMOS SSPA Controller Rev3.0.1 (ZIP file contains the RS-274X Gerber files, and BOM & CPL files for the SMD components)

PIN Layout: Rev 3.0.1/2 Pinout

Schematic: OUTPUTS
Schematic: Antenna Power and SWR circuit
Schematic: LPF SWR circuit

17 May 2023: Components are soldered. Still waiting for few parts to arrive, but I can start coding now [Rev 3.0].

KEEP THE BALL ROLLING:
Apart from countless hours (and lots of coffee) to design the circuit, testing, coding thousands of line etc (In addition to my full time work) – I also had to order every component from of-shore for my experiment. As I do not sell KIT – there is no return except my own happiness.

If you like my work and wish to use it – you may show your appreciation and support my effort by a small donation. This is completely optional and has no effect on the support I try to provide over email/chat/Github. 73, S21RC

This Post Has 36 Comments

  1. Branko

    Hi Rabby

    I just finished upgrading my SSPA to liquid cooling and TFT screen using lite version. Works OK, but I needed to add some filtering (inductors, capacitors) at relay driver (using TD62783) as there was some problem with RFI.
    Just it is hard to properly adjust readings for REW RF power. Also I haven’t managed to work with 2 DS18B20 sensors (just 1 works, but I use 2 pallets). I adopetd the code to add STAND BUY / OPERATE BUTTON on the display, to take put QRO in stand buy mode when I wish. I’m not using rotating band select switch. I also changed the display bottons as my LPF has 3 bands on the same botton (the sam LPF for 20, 18 and 15m). I have some pictures on QRZ.COM.
    I’m planing to upgrade on ver 3 as the Tennsy is much faster and to use BCD/CIV decoders for LPF switching.
    Perhaps someone has finished the project with ver 3 and have some PCB avalable? I’m interested to buy PCB if awailable.

    vy 73, Branko, S52V

  2. Jasper

    very interestting project, as i made myself simular project ( not this fancy looking) will consider my next build of new SSPA for 6m ( 50Mhz) to try this. nextion designed software looking fantastic !! If some1 did order too many boards and want to share teh cost with me please let me know.

    cheers 73′
    Jasper PA2J

    1. Fazlay

      Hello Jesper, thanks for comment. You can look into the “s21rc sspa controller” facebook group where people discuss and also swap extra pcb. Thanks, s21rc

      1. Jasper (PA2J)

        Thanks for the Reply Fazlay ! do not have FaceBook 🙂
        but will will find a way. I it possible to edit the Nextion part because want to leave out some parts and change colors…
        wit the TFT now editting is not possible ( what i perfectly understand because of the hudge work it contains)
        Thanks again

        1. Fazlay

          Hi Jesper, the editable HMI is also given, please check the display section in the github repo. You can use Nextion Editor to edit change display layout/content. 73, S21RC

  3. PROBIR

    Use a DC DC converter and set it to 7volt – the dissipation will reduce appreciably. Board ordered – Another week to arrive

  4. Nicolas VE2NNX

    Hello Rabby,
    I just received 5 boards populated, begin testing… I put a 7805 1.5 amp… but still geting very hot. I may hav to add a separate regulator just to feed the Nextion. That ok anyway i will put the screen in a separete case, it will fit better on the desk away from the amplifier, 73

  5. S21RC

    Hi Madhu,
    V3.0.2(Gerber 3.0.2b) is usable and few OM making it already (update you can see in the facebook group). We are doing small software tuning and working on added features now (CAT over Bluetooth, remote monitoring over web etc).

    Thanks, s21rc

  6. Madhu

    Hai Fazlay,

    Any new update of SSPA V3 PCB dovelopments ?

    Regards,
    Madhu.

  7. Probir

    Thanks

  8. PROBIR

    Hi Rabby,

    Good to see the version3.0 all files are out in the repository. Thanks for hard and good work,
    Unfortunately, the schematics is missing which is actually very important for me probably for others.
    It will be nice if you can upload a pdf file in Monochrome that will help to get a good print out

    1. s21rc

      Hello Probir ji,
      The schematic is almost done (OM F8FQX is kind enough to draw it with kicad), doing final check for minor label correction. A draft version is already shared in the facebook group s21rc sspa controller. I will upload it in the repo once all the correction is done.

  9. Madhu

    Dear Fazlay,

    If I have to assemble with my own risk, how I get the PCB,circuit details and softwares
    Regards,
    Madhu.

    1. Fazlay

      Hello Madhu,
      As the project is still in progress thats why the disclaimer has been added.

      All codes (mcu code, display code), pcb gerber for fabrication house, CPL and BOM for PCBA service etc are in the github, github.com/s21rc

      As these project used Surface Mount components- good soldering skill is needed.

      I usually make the PCB from JLC PCB, China. Thanks, 73, s21rc

      1. Madhu

        Thank you Fazlay for qick replay.
        Which bom code for request pcb from JLC ? Or how can request a pcb?

        Regards,
        Madhu.

  10. Madhu

    Hai
    I am very intrested thos board. Fully asseble vertion available?

    Regards,
    Madhu
    VU3MQK/A65DE.

    1. Fazlay

      Hello Madhu, I do not have the option to send PCB/Circuit abroad (Local post do not allow). Its a open source project and you have to make it your self. There are few OM sharing their PCB as they have extra – you will find the offers in facebook SSPA groups. I have got your email with suggestions – thanks. Will reply in detail later. 73, S21RC

  11. Probir VU2BQF

    Hope you are Back

    1. s21rc

      Hello OM Probir, Yes I am back to Dhaka and resumed this project. New code uploaded – Basic functions working – now doing CIV implimentation.

    2. PROBIR

      Great you resumed your project …closely checking the status ONCE i see all working fine I will order the PCB Thanks

  12. PROBIR

    BTW, could you please provide me the part # of LCD Display

    1. Fazlay

      You can use any 5″, 7″ Nextion Display (800×480 pixel). My test version is a 5″ Nextion Enhanced (NX8048K050).

  13. PROBIR

    Great feedback. Yes, time to download the Gerber. To my wish list if the Power readout can be 2killowatt – that will be awesome

    1. Fazlay

      Yes, the new UI has enough space to show 4 digit.

    2. kg5qqw

      who are you using to make the pcb

      1. s21rc

        Hi OM, I use JLCPCB to make the PCB. Thanks, S21RC

  14. PROBIR

    Hi Rabby,

    Just got involved in my MQTH work and could not keep a track . Is 3.0 hardware is tested or the package is yet to come. I need to order quite a no. of PCBs and wandering I can place order for 3.0 boards too. kindly update me the present status — i know you are equally busy with your MQTH work

    1. s21rc

      Hello Probir ji,
      Found some problem during the test, corrected it. The final layout will be ready by tomorrow I hope. You can order PCB then. Thanks, S21RC

      1. s21rc

        Hello Prabir, I have uploaded the updated Gerber/BOM and CPL. I have also ordered few boards from JLC assembled (only the SMD components). You may use the gerber to order PCB if needed. Thanks, S21RC

  15. Dana VE3DS

    Rabby I am interested also

  16. Denis

    Please share a schematich diagram
    Thanks

  17. López Cesar

    I wish to receive information

  18. Probir

    S21RC SSPA Controller Hardware Rev 3.0 PCB looks nice. Did you get a chance to work on this further.

    1. Fazlay

      Hi Probir ji, there was an IC package type error in the board, still waiting for the corrected version.

  19. Nicolas VE2NNX

    hello my friend, excellent work again, looking forward your test on rev3 board and you approuval that everything is OK to order mine 😉
    to bad you used pin 9 of the teensy 4.1, it is reseved for frequency mesurement, so you can implement auto sense band select feature. check the link
    https://www.pjrc.com/teensy/td_libs_FreqCount.html
    if you did make more than 1 prototype board and you have one loose, i am ready to buy one direct from you… let me know
    75

    1. Rabby

      Hi Nicolas,
      with Teensy4.1 you can use the frequency measurement using any/all FlexPWM pins, unfortunately the spare pins (26-27,32) left for future features do not support it.

      btw, additional circuitry is needed for bringning the RF to TTL level, and also may need some divider to measures upto 10m.

      I will let you know the result, and update this page with more info as progress. Thanks, 73, S21RC

Leave a Reply