Component Advice Please?

[dilwyn]

Nice work! The software looks relatively straightforward if you can program it from BASIC like that.

Derek - good luck with sorting out the I2C interfaces, especially if it means we can use them on Q68 one day!

[Derek_Stewart]

Nice work! The software looks relatively straightforward if you can program it from BASIC like that.

Derek - good luck with sorting out the I2C interfaces, especially if it means we can use them on Q68 one day!

Hi Dilwyn,

I hope that the TF Services I2C interfaces can resurrected and made available.

But as time marches on the same interfaces can be made with smaller parts and maybe off the shelf. Whether they would work with the TF Servicex code, I have yet to look into.

[t0nyt]

Nice work! The software looks relatively straightforward if you can program it from BASIC like that.

I kept looking at the code and couldn't understand why it needed to send 4 times for each byte to display (instead of 2 x 4bits), so have edited out the send at lines 100/120 & deleted line 220 and it still works fine

Am trying to find some kind of command specification for the PCF8574 to understand what the config routine does and what other options are available

I think it would be nice to create something like an "LCD(<line>,<row>,<text>) " extension for BASIC (which may also improve the speed if it's in assembler)

Code: Select all

30  PROC_INIT
40  DIM M$(40) : M$="SINCLAIR QL         Minerva v1.98 Mk2"
50  FOR C=1 TO LEN(M$)
60   D$=M$(C TO C)
70   C%=CODE(D$)
80   H%=(C% && HEX('F0')) || HEX('09')
90   L%=((C%*16) && HEX('F0')) || HEX('09')
100   D%=H%
110   PROC_EN
120   D%=L%
130   PROC_EN
140 NEXT C
150 STOP
160  DEFine PROCedure PROC_INIT
170   DATA HEX('38'),HEX('38'),HEX('38'),HEX('28'),HEX('28'),HEX('88')
175   DATA HEX('08'),HEX('88'),HEX('08'),HEX('18'),HEX('08'),HEX('68')
180   DATA HEX('08'),HEX('E8'),HEX('88'),HEX('08')
190   RESTORE 170
200   FOR D=0 TO 15
210    READ D%
230    PROC_EN
240   NEXT D
250  END DEFine
260  DEFine PROCedure PROC_EN
270   D%=D% || HEX('04')
280   I2CTXB(D%) : REMark *I2CTXB 3F D%
290   D%=D% && HEX('FB')
300   I2CTXB(D%) : REMark *I2CTXB 3F D%
310  END DEFine
500  DEFine PROCedure I2CTXB(D%)
510   LOCal r$
520   r$=I2C_IO(CHR$(164) & CHR$(D%) & CHR$(255),0,HEX('27'),1)
530  END DEFine

[t0nyt]

With regards to attaching the LCD to a MK2 Remake the vBat (not used for LCD) is the pin on J2 nearest the crystal

The LCD seems happy to draw it's power from the 5v pin

[Derek_Stewart]

Hi,

The VBAT is not part of the I2C Interface, but Voltage BATtery

I have ordered a similiar LCD, which has anArchino s8oldered to the back of the LCD, where the I2C Interface is connected.

I assume yhe I2C Address is setup in the Arduino.

I will try it on a Q68 I2C, which can use 5v I2C devices.

[t0nyt]

Hi,

The VBAT is not part of the I2C Interface, but Voltage BATtery

I have ordered a similiar LCD, which has anArchino s8oldered to the back of the LCD, where the I2C Interface is connected.

I assume yhe I2C Address is setup in the Arduino.

I will try it on a Q68 I2C, which can use 5v I2C devices.

I don't know the Q68. For QL the LCD only needs the PCF8574 control board, but not an Arduino.

I mean you only need the LCD with PCF8574 for QL with Minerva Mk2 (or any I2C connection I believe)

Edit: most of these devices are made FOR USE with arduino, which is fine

[t0nyt]

The I2c address of the PCF8574 is defaulted to either $27 (TI make) or $3f (NXP make) but there are 3 jumpers that can be soldered to change the address if needed (so you can have multiple LCD's on same I2c BUS)

[t0nyt]

A slight code mod to make use of all 4 rows (note that the order of the text is line 1, line 3, line 2, line 4)

Code: Select all

40  DIM M$(80) : M$="SINCLAIR QL         Minerva v1.98 Mk2   Line 2              Line 4"