The last report indicated that the circuit boards for the QVGA Controller/Display module were in fabrication. I received them a week ago and discovered to my horror that I had not “turned on” the Power and Ground layers of these 4–layer boards. Nothing to do but reorder. So I corrected and re-ordered. I should have them again in a few more days. A mistake that I wish never happened but it did. It is the consequences of insufficient checks and balances.
I continue working on the software for the QVGA Controller/Display module. The major pieces in development right now are:
- Interface with VGDD to allow screens to be developed and incorporated in the QVGA Controller/Display program. This function has reached a milestone in that we have a working “round-trip” method where we can create a screen, incorporate and run it on the QVGA Controller/Display and then make changes and repeat the process as necessary.
- The Firmware structure of the QVGA Controller/Display
- Initialize the UART
- Creation of a data base for the sending/receiving of messages.
- Create a table-driven CRC function.
- Serial Receive Interrupt Routine.
- Serial Transmit Interrupt Routine.
- Receive a MODBUS packet, test for proper CRC.
- Save a packet data into data base. (still working on some function codes)
- Create a SCANNER function to extract data variables from the Amp Module data base and keep the Screen updated.
- Create transmit packets.
I am continuing to flesh-out function codes for received packets. I discovered that the CRC function has a bug for a certain message data combination. I must resolve this. It is a pretty tough problem to find.
I hope to have an assembled QVGA Controller/Display in the next week or so. I plan to get the above mentioned software finished so I can concentrate on the actual application screens and communicate with the amp.
HF Projects sales is slow and continues as a small trickle. It requires that I spend more time away from the project to keep everything moving forward.
73 K5OOR – Virgil