Search found 145 matches
- Thu Jul 06, 2023 8:02 pm
- Forum: General discussion
- Topic: Can’t read AppleII 8-bit Data Bus with Blue Pill
- Replies: 19
- Views: 2352
Re: Can’t read AppleII 8-bit Data Bus with Blue Pill
That code was for Apple 2. I am not familiar with its hardware , but code should be same: code1.jpg I can't say much about execution time of code generated with compilers, but i know that it's never one instruction per one CPU cycle. Anyway, by looking at datasheet you posted in first post, i still ...
- Thu Jul 06, 2023 3:26 pm
- Forum: General discussion
- Topic: Can’t read AppleII 8-bit Data Bus with Blue Pill
- Replies: 19
- Views: 2352
Re: Can’t read AppleII 8-bit Data Bus with Blue Pill
So appears to be working? My mistake, i missed value <<= 1; Unfortunately, until you measure bluepill's interrupt latency i can't say in what point in time you are reading data bus. But don't forget that you have info on BUS01, DS and RW also, so you can guess when the reading is done. I don't thin...
- Wed Jul 05, 2023 9:41 pm
- Forum: General discussion
- Topic: Can’t read AppleII 8-bit Data Bus with Blue Pill
- Replies: 19
- Views: 2352
Re: Can’t read AppleII 8-bit Data Bus with Blue Pill
This is little confusing for me: uint32_t displaymask = 1 << 31; if (value & displaymask) } Did you mean if (value & c) 1. not sure why you needed the while loop in the DS_ISR() -> it wouldn't be triggered unless you are on a falling edge. It's because 6502 timing. Adrress and RW is stable 3...
- Wed Jul 05, 2023 3:42 pm
- Forum: General discussion
- Topic: Can’t read AppleII 8-bit Data Bus with Blue Pill
- Replies: 19
- Views: 2352
Re: Can’t read AppleII 8-bit Data Bus with Blue Pill
As i recall from 6502 timings, your goal is to read data bus at rising edge of BUS0. . Maybe you are reading data bus too late. Try to attach interrupt at falling edge of DS , and while BUS0 is low, keep reading data bus... attachInterrupt(digitalPinToInterrupt(DS), DS_ISR, FALLING); volatile uint32...
- Sun Apr 30, 2023 10:17 pm
- Forum: Code snippets
- Topic: STM32F411CE hardware encoder
- Replies: 0
- Views: 8565
STM32F411CE hardware encoder
Hello After having some experiments with encoder on breadboard with STM32F411CE (WeAct board), i am made simple example to use it with timer working in hardware encoder mode. Tested with all combinations of pins that can be used for encoder input. I didn't use any debounce hardware, encoder module h...
- Thu Apr 27, 2023 7:38 pm
- Forum: General discussion
- Topic: HardwareTimer fast PWM Interrupt crashing
- Replies: 2
- Views: 1271
Re: HardwareTimer fast PWM Interrupt crashing
IMHO, you reached maximum of what interrupt with timer can do. Interrupt latency can be a killer. You still have few options: - try to compile with O3 (without or with LTO) - try precalculated code for uint32_t GPIOE->BSSR = uint32_t value[xx] where value is not just CLK and MOSI bits, but also nSS1...
- Mon Feb 27, 2023 6:42 pm
- Forum: USB bootloader
- Topic: bootloader seems to get overwritten
- Replies: 10
- Views: 12912
Re: bootloader seems to get overwritten
That parts reads a bit confusing. Why does the port change? Does it change on every update? Or are you saying there is one port for the flashing and another for the serial monitor? No, it will do only once, when you upload your first sketch on just flashed bootloader. Every upload after that is don...
- Mon Feb 27, 2023 4:12 pm
- Forum: USB bootloader
- Topic: bootloader seems to get overwritten
- Replies: 10
- Views: 12912
Re: bootloader seems to get overwritten
I don't know how to deal with PIO, but with Arduino IDE, once you flashed "generic_boot20_pc13.bin" via serial or st-link, you'll get COM port (and it will be named "COM10 Maple Mini"). Port number may be different in your case. At this point use you must use USB to upload sketch...
- Mon Feb 06, 2023 1:10 am
- Forum: General discussion
- Topic: DMA Code not working on STM32F401 blackpill
- Replies: 4
- Views: 1393
Re: DMA Code not working on STM32F401 blackpill
Few errors here: First, you used Stream6, channel0 , which is used for (timer1) ch1 or ch2 or ch3 but later you try to call it with "TIM_DMA_UPDATE" (which use Stream5, channel6). Second, your "data" is 8 bit, and GPIO port is 16bit wide (register is 32bit, but 16 is used). If yo...
- Sat Dec 17, 2022 10:00 pm
- Forum: General discussion
- Topic: STM32 TVout Upgrade to Work with Video Overlay - Help Needed
- Replies: 7
- Views: 1731
Re: STM32 TVout Upgrade to Work with Video Overlay - Help Needed
I did some experiments with TV/VGA and stm32f401/411 few years back, so i'm kind of familiar with NTSC/PAL timings. I did quick look at lm1881 datasheet, i would say that what are you trying to do is doable, but timing critical. In short, all you need to do is to send your line data from scanline 23...