Board 50227

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Revision as of 21:35, 1 July 2021 by Lucas (talk | contribs) (display mapping)
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Datasheet-display-50227-back.jpg Datasheet-display-50227-front.jpg

Seems similar to the 50229 board, but other display type (DLO1414 vs PD4435), other MCU (atmega161 where 50229 has a '162), and more buttons.

Seems like we have just 1 of this board. It might be similar to Bestand:IMG_8958.jpeg which then would be a second one.

buttons

4 extra buttons; wired between row 0/1, row 1/2 and col 1/2, col 2/3.

display mapping

6 displays (DLO1414) - mapped per below; with from left to right in each screen '3210'.

Datasheet-display-50227-dmap.jpg

Displays zitten aangesloten volgens het voorbeeld uit de datasheet, op de 74HC138 rechtsboven de atmega161.

Display schematic 50227.

Echter, er worden meer enable-pinnen gebruikt dan in het voorbeeld schema. Zie onderstaande tabel. Tussen haakjes de namen uit de 74HC138 datasheet achter de namen uit het voorbeeldschema.

Atmega161 74hc138
pin 24 PC3 A (A0)
pin 25 PC4 B (A1)
pin 26 PC5 C (A2)
pin 27 PC6 G (E3)
pin 28 PC7 (nE1)
pin 16 PD6 nWR (nE2)

De datalijnen D0-D6 zitten op PA0-PA6 van de atmega161 (pin 39 PA0 tot pin 33 PA6). Er is bij dit type display geen D7.

reading the buttons

The 21 buttons are mostly in a 4x4 matrix. Every switch is between two MCU pins. The pins not fitting in the matrix are between 2 rows or 2 collumns.

The buttons 1, 2, 3 on the left are named 1, 2, 3 in the tables as well. The buttons labeled 1, 2, 3 on the right are labeled 1' 2' 3' as these are not in parallel with the others labeled 1, 2, 3.


row/col PD2 PD3 PD4 PD5
PB3 36C 2' 3 04
PB2 24 18C 1 2
PB1 27 36R 36L 1'
PB0 HELI 09 18L 18R

The keys that are between 2 row lines or between 2 collumn lines can be re-fitted in another matrix: (Possibly other configurations are possible and maybe even more efficient! By choosing other row/col lines in software for the same hardware)

row/col PD5 PB2 PD3 PB0
PD4 3' . EXEC .
PB3 . CORR . .
PB1 . 22 . 06

The keys are thus NOT the same als on 50229.

Read as any other keyboard matrix (? Enable pull-ups on input row/col s & unused col/row and drive one col/row low ?)

LEDS

Todo! (Might be different from 50229 also... Though same circuit with a 74hc138 and 74hc174 seems to have been applied, it might be connected to different IO lines compared to 50229... )