my name is Reinhard and I'm new to this forum.
After a long time, I pulled out my old Sinclair QL computer and detected the possibility to attach it via the GBS8200 card to
a VGA flatscreen monitor.
As I already had som NodeMCU boards lying around, I ordered a GBS8200 card, that arrived lately.
I already flashed the NodeMCU with the data from github and connected board and MCU.
My problem now is, I nearly never get a display on the monitor.
When I connect the pure GBS board, there is no problem to get the display onto the monitor screen, whatever resolution I set
up (640x480, 800x600, 1024x768, 1360x768). But with NodeMCU connected, there are rare chances where I get a display, but only
for about half a minute. Then the display gets black with a monitor message of "Out of Frequency"; and normally it doesn't
recover anymore.
The available signals from the Sinclair QL are R,G,B, vertical sync anf composite sync (H + V), all of them with full 5 Volt
TTL level. According to the sync pulses, the signal is 50Hz vertical and about 15 Khz horizontal.
To adapt the levels I removed the R,G,B pots and replaced them with 422 Ohm resistors. For the sync signals I added voltage
deviders (70:100 Ohm). Now the R,G,B levels are 630 mVss and the sync signals are 2.6 Vss.
I connected the composite sync with the S pin and the V sync with the V pin of the board.
Power is supplied from a 5Volt 2.5A power supply via the round connector and the NodeMCUis connected to P9 (==>vin)
SDA, SCL and the debug wire are connected and the jumper is plugged.
The MCU LED near the D0 pin is off most of the time, and blinks randomly at random duration.
The web server is working, that means, I can connect my PC and get the menu with the many green keys. But I really don't know
what I can do with it, especially, when there is no display on my monitor. When I activate some of the keys, I get different
data/messages displayed in the message window at the bottom of the screen.
What have I overlooked, done wrong ?
How can I get further.
Reinhard
Spoiler
Code: Select all
The following is a log from a situation, where the monitor synchronized and displayed a correct content (for half a minute).
The GBS board is already powered on, Sinclair QL switched on after some time. It then took some time until the display showed
up for about half a minute and then the screen went black with the "Out of Frequency" message of the monitor.
Station disconnected, reason: 201
Station disconnected, reason: 201
.
.
.
Station disconnected, reason: 201
Station disconnected, reason: 201
(WiFi): AP mode (SSID: gbscontrol, pass 'qqqqqqqq'): Access 'gbscontrol.local' in your browser
>>>>>>>>>>>>>>>>> Here, I powered on the computer >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> there is still no display on the monitor >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Activity detected, input: RGB
VSync: present
HSync: present (with CSync)
RGB/HV (CSync)
RGB/HV upscale mode
50.28
ADC offset: R:44 G:41 B:41
preset applied: 768x576 for scaling RGB (CSync)
Note: scaling RGB is still in development
(H-PLL) rate: 977 state (no change): 1
`HTotal Adjust: -23, source Hz: 50.124, output Hz: 50.215
`````````
h: 431 v: 623 PLL:0 A:4a4a4a S:a7.10.30 H- I:40 D:8000 m:14 ht:2345 vt: 313 hpw: 175 u: 0 s:66 S:13 W:31
h: 431 v: 623 PLL:0 A:4c4c4c S:a7.10.30 H- I:40 D:8000 m:14 ht:2345 vt: 312 hpw: 175 u: 0 s:68 S:13 W:31
h: 431 v: 624 PLL:0 A:4e4e4e S:a7.10.30 H- I:40 D:8000 m:14 ht:2345 vt: 312 hpw: 175 u: 0 s:76 S:13 W:31
h: 431 v: 623 PLL:1 A:505050 S:a7.10.30 H- I:40 D:8080 m:14 ht:2345 vt: 313 hpw: 175 u: 0 s:8a S:13 W:31
`h: 431 v: 622 PLL:1 A:525252 S:a7.10.30 H- I:40 D:0000 m:14 ht:2345 vt: 313 hpw: 175 u: 0 s:76 S:13 W:31
``````````````````````````````````````````````<reset>
Activity detected, input: RGB
VSync: present
HSync: present (with CSync)
RGB/HV (CSync)
(SP) HS active low
(H-PLL) rate: 977 state: 1
RGB/HV upscale mode
50.28
ADC offset: R:44 G:41 B:41
preset applied: 768x576 for scaling RGB (CSync)
Note: scaling RGB is still in development
HTotal Adjust: -19, source Hz: 50.124, output Hz: 50.137
>>>>>>>>>>>>>>>>>>>>>>>>> The display shows up >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
``````````````````````````````````````````````````<reset>
>>>>>>>>>>>>>>>>>> with the "<reset>" the display gets and stays black: "Out of Frequency" >>>>>>>>>>>>>>>>>>>>
Activity detected, input: RGB
VSync: present
HSync: present (with CSync)
RGB/HV (CSync)
(H-PLL) rate: 977 state: 1
``````````<reset>
Activity detected, input: RGB
VSync: present
HSync: present (with CSync)
RGB/HV (CSync)
(H-PLL) rate: 977 state: 1
``````````<reset>
Activity detected, input: RGB
VSync: present
HSync: present (with CSync)
RGB/HV (CSync)
(H-PLL) rate: 977 state: 1
`````` RGB/HV upscale mode
49.96
ADC offset: R:44 G:41 B:41
preset applied: 768x576 for scaling RGB (CSync)
Note: scaling RGB is still in development
`````HTotal Adjust: -19, source Hz: 50.124, output Hz: 50.137