TI-58C Clone

[Marc van Lemmen]

Hello Pierre,

It works ! It turns out it was not necessary to program the 328p, it was already loaded with the right program. ( But in the meantime I now know how to program an empty 328p, and to compile a new .hex file )
I'll post some photo's in the next week.

Kind regards,
Marc.

[Pierre]

(11-10-2024 09:44 AM)Marc van Lemmen Wrote:  Hello Pierre,

It works ! It turns out it was not necessary to program the 328p, it was already loaded with the right program. ( But in the meantime I now know how to program an empty 328p, and to compile a new .hex file )
I'll post some photo's in the next week.

Kind regards,
Marc.

Congratulations!

Glad to hear that the firmware was already flashed. (I assumed so considering the lack of instructions on this topic on Miroslav's site)

I didn't look at the ET-58 circuit that I received already assembled.
Is there a 6-pin connector? (MISO, SCK, RST, VTG, MOSI, GND)

The "Voyager" PX calculators (11C, 12C, 15C...) that have an Atmega microcontroller have this kind of connector.
It allows firmware update with AVRdude and a USBasp interface which is pretty easy to use.

And I will wait to see the photos...

[Marc van Lemmen]

Hello Pierre,

There's no ICSP connection on board, and the usb connection is only used for 5v, there are no data pins connected. I'll see if I can make an ICSP connector of some sort.

For now I'm unable to read the working 328p, and the 328p I programmed myself won't work. That may be a clock issue, I'm not sure.

Kind regards,
Marc.

[Pierre]

(11-10-2024 05:56 PM)Marc van Lemmen Wrote:  For now I'm unable to read the working 328p, and the 328p I programmed myself won't work. That may be a clock issue, I'm not sure.

On Miroslaw's website there are few indications :

Quote:Processor Programming:
When programming the ATmega328P processor, use the following settings for the fuses: low 42 (default 62), high D1 (default D9), ext FE (default FF). When the calculator is turned on, the logo and text ET-58 221129 (build version) is displayed. If the ROM checksum does not match, the calculator will report an error instead.

Nothing more...

[Marc van Lemmen]

I've used the right fuses, but the 328p I flashed myself doesn't work. I've reflashed it several times but with the same result. The strange thing is, I can't communicate with the working 328p. So I think it is a clock issue, because the baudrate to communicate with the 328p depends on the clock speed. I'll keep searching ! .........

[Marc van Lemmen]

Hi,

Here are some photo's from the assembly/soldering of the ET-58.
I followed the English construction steps on https://www.breatharian.eu/hw/et58/index_en.html.
Only the step to program your 328p is not necessary. Since there are not so many components ( except for 45 keys ! ), I've not so many pictures.
The smd mosfet and the usb connector where the most difficult for me to solder.

I'm not sure if I leave the 328p in an IC socket, so I'll wait with the top and bottom cover.

In the last photo the calculator operates on the 3V Cr2032. So no backlight.

Kind regards,
Marc.

[Pierre]

(11-11-2024 09:51 PM)Marc van Lemmen Wrote:  Here are some photo's from the assembly/soldering of the ET-58.

Congratulations for this remarkable work !
And thanks for the pictures.
The IC socket was not in the kit! (???)
It must cause an extra thickness?

Otherwise, for the ISP connector it is on the ET-57 that I had seen it.
https://www.breatharian.eu/hw/et57/index_en.html

Best regards
Pierre

[Marc van Lemmen]

(11-11-2024 10:43 PM)Pierre Wrote:  

(11-11-2024 09:51 PM)Marc van Lemmen Wrote:  Here are some photo's from the assembly/soldering of the ET-58.

Congratulations for this remarkable work !
And thanks for the pictures.
The IC socket was not in the kit! (???)
It must cause an extra thickness?

Otherwise, for the ISP connector it is on the ET-57 that I had seen it.
https://www.breatharian.eu/hw/et57/index_en.html

Best regards
Pierre

Hi Pierre,

Thanks ! The IC socket was not in the kit, I used it because I thought I had to program the 328p and had no way to test it other than on the ET-58 board itself. ( And because there's no ISP connector ).
At the moment I'm printing some new spacers to see if it is workable, only a very small part of the switch extends above the top. I'll keep you informed .......

Kind regards,
Marc.

[Marc van Lemmen]

Hi,

I've put the top and bottom on the ET-58, and I can work with it. But I'm going to look if I can make an ISP connector so I can solder the 328p to the board.

Kind regards,
Marc.

[AnnoyedOne]

(11-10-2024 10:15 AM)Pierre Wrote:  Is there a 6-pin connector? (MISO, SCK, RST, VTG, MOSI, GND)

That is SPI (Serial Peripheral Interface) invented by Motorola (now Freescale). Essentially a shift-register.

Looking at section 27.8 of the 328P datasheet (Serial Downloading) it is "programmed" via the SPI. Not serial (UART). Not USB.

The datasheet doesn't say but SPI is master/slave. I assume that in ICSP (In-Circuit System Program) mode that the 328p is a slave. If so any clock should be provided by the master (programmer).

A1

PS: The 328P also has a parallel program mode (datasheet section 27.6 & 27.7).

[Marc van Lemmen]

Hi,

I've been able to program my own 328p with the ET-58 firmware, and it works ! After reading the fuses of the 328p that was delivered in the kit it turned out that te efuse must be 06 and not FE as stated in the building instructions on the ET-58 website.
(with newly compiled .bin file the calculator gives a CRC error, but it works. Not sure if everything works ...........)

Kind regards, Marc.

[Pierre]

(11-17-2024 04:28 PM)Marc van Lemmen Wrote:  I've been able to program my own 328p with the ET-58 firmware, and it works ! After reading the fuses of the 328p that was delivered in the kit it turned out that te efuse must be 06 and not FE as stated in the building instructions on the ET-58 website.
(with newly compiled .bin file the calculator gives a CRC error, but it works. Not sure if everything works ...........)

Hi Marc,

Well done ! Great job !

Have you backed up the ET-58 firmware before?
I suspect that Miroslav's (breatharian or github site) is not exactly the same as the one preloaded by Pajenicko...
The ET-58 version says "ET-58 221129 http://www.pajenicko.cz" obtained by using OP 8A on the calculator (Keystrokes: 2nd 9 8 2nd 2nd 4).
On github, Miroslav's versions are indeed mentioned as "build 221129".

Best regards
Pierre

[Marc van Lemmen]

(11-17-2024 05:32 PM)Pierre Wrote:  

(11-17-2024 04:28 PM)Marc van Lemmen Wrote:  I've been able to program my own 328p with the ET-58 firmware, and it works ! After reading the fuses of the 328p that was delivered in the kit it turned out that te efuse must be 06 and not FE as stated in the building instructions on the ET-58 website.
(with newly compiled .bin file the calculator gives a CRC error, but it works. Not sure if everything works ...........)

Hi Marc,

Well done ! Great job !

Have you backed up the ET-58 firmware before?
I suspect that Miroslav's (breatharian or github site) is not exactly the same as the one preloaded by Pajenicko...
The ET-58 version says "ET-58 221129 http://www.pajenicko.cz" obtained by using OP 8A on the calculator (Keystrokes: 2nd 9 8 2nd 2nd 4).
On github, Miroslav's versions are indeed mentioned as "build 221129".

Best regards
Pierre

Hi Pierre,

I've used a new fresh 328p and put the backed up the firmware from the good working 328p in it, no crc error.
If I use the ET58.bin in the .zip file from the github page ( compiled in 2022 ) the calculator also starts normal !
Only when I use the c.bat in ET-58-src ( .zip from the github page ) to compile a new ET58.bin, it gives the crc error ( crc = 241117 ). I'll keep searching

Kind regrads,
Marc.

[Marc van Lemmen]

Hi Pierre,

I've compared the working .bin to the newly compiled .bin and there where 5 bytes different. Three bytes from the date (29-11-22 ) / crc message ( h06E9, h6EC and h6ED ) and the last two bytes of the .bin file ( h7C02 and h7C03 ). When I change those bytes to the values of the working binary it works without warning !
I've tryed some library programs ( reactio time, mars landing and diagnostics ) and the OP 4F pixel switching demo, no problem.

Kind regards,
Marc.