I have a board including stm32f767 .The LTDC unit is set and the LCD works well.I want to define an array in the SDRAM. I defined it in the Address: 0XCF000000 that does not have overlap with the LCD frame buffer:
u16 Buffertest[200] attribute((at(0XCF000000)))
But when I run the program, the LCD was hanged.
I would be grateful to hear your guidance.
Kind regards
If you use the external SDRAM, your data has to be 4byte aligned. So you cannot use a 16 bit array. All your values have to be 32 bit. So change your array type to an u32.
Related
I'm working on transceiving data on stm32F04xx. When I transmit data from the MCU at lower speed, it looks like if the baudrate was wrong and I get a bunch of question marks. When I increate transmission speed. I can read the data I'm sending. I've used to stm32cubeIDE to generate a simple UART code and only added
HAL_UART_Transmit(&huart2, "test\r\n", sizeof("test\r\n"), 1000);
HAL_Delay(500);
in the while loop.
On my NUCLEO-F042K6 evaluation board, I don't see any issues printing data on the tty port. But I have another device which uses the same stm32f042xx chip that only works when transmitting UART data at higher speed. so when i change my delay to something like 80 milliseconds, I can read the data flow.
I've attempted to flash the same binary that I flashed on my evaluation board on the other MCU I have but again the data only readable at higher transmission speed.
I'm flashing the MCU with stm32flash tool so I don't know if that can make a difference where on the eval board, I'm using the stm32cubeIDE to flash it.
I'm not sure what's going on here, I've tried different baudrates and different clock configurations and that doesn't seem to help too.
What could possibly cause the data to be unreadable like if the baudrate was wrong when transmitting at low speed?
I am working on the MLX90614 IR sensor. In the datasheet, they have given some steps to put the sensor but somehow I am not able to understand it clearly. A detailed description of the RAM and EEPROM access is given there. However, how to put the sensor in sleep mode is not much clear.
In another section of commands, they have given an opcode for entering sleep mode. But again there is no much information about usage of the opCode.
I am quite successful in using the sensor to read the object's temperature. But putting sleep mode is not helping me anywhere.
As per page 22 of the datasheet, you need to send a write with 0xFF to the sensor.
PEC is some CRC and and they apparently already did the math for you.
So you need to send:
0xB4 0xFF 0xE8
(Double check the I2C address and read/write bit, I'm never sure if the given address is shifted or not. Edit: 0xB4 is shifted and 8th bit 0 for write already added, so no need to do anything else).
I'm trying to run the code below on an ESP32 TTGO T-display running micropython from loboris. (It's esp32 pre-loaded with display drivers for TTGO Display) I have attached a GY-906 temp sensor through i2c for testing. i2c.scan() finds it without issue on 0x5a [80] like it is supposed to, but when I request temperature data, the response is always 0xFF instead of proper temperature readings.
When I run the exact same code on a WeMos D1 (only difference is the pin numbers) I get temperature data returned. I am attaching both logic analyzer screenshots hoping someone can tell me what I need to do differently. Both are directly wired from 3.3, gnd, and the 2 i2c pins.
Things I have tried: adding pull up resistors to SDA, SLC (10k, 1k, 100). Switching to different i2c pins. Result seems to be the same. What am I missing? Is there supposed to be a resistor somewhere I don't know about? Other hardware? The screenshots make me think that the GY906 is responding, just the wrong response value.
Main Code
import temp_sensor
Pin = machine.Pin
I2C = machine.I2C
i2c = machine.I2C(0, scl=Pin(22), sda=Pin(21), freq=100000)
temp1 = temp_sensor.Temp.init(i2c)
print(temp1.read_object_temp())
time.sleep(1)
print(temp1.read_object_temp())
time.sleep(1)
print(temp1.read_object_temp())
time.sleep(1)
print(temp1.read_object_temp())
temp_sensor.py
import mlx90614 ##From https://github.com/mcauser/micropython-mlx90614
class Temp():
def init(i2c):
try:
sensor = mlx90614.MLX90614(i2c)
except:
print('couldnt connect to an i2c temp sensor')
sensor = False
else:
print('temp found')
#return sensor
finally:
return sensor
bad esp32 TTGO T-Display:
good 8266:
For anyone receiving 1037.55 responses from your gy-906 or MXL90614 sensor, that translates to 0xFF, 0xFF or all high (ones) from the sensor. This seems to happen when the sensor doesn't understand how to respond. (Thank you, #jasonharper for helping me understand this)
Here's how the math works:
The 0xFF, 0xFF in decimal is 65535.
The sensor resolution is 1/50 of
a degree which means you divide 65535 x 0.02 to convert to Kelvin, or
1310.7 (K)
Kelvin to Celsius (subtract 237.15) gets you 1037.55 C
Celsius to Fahrenheit gets you 1899.59 F
Bottom line, your sensor is hiccuping because it doesn't like the stop bit between the write and read, or you have a problem with your I2C bus, either the protocol is doing the request wrong or you have a cabling issue (length or wire gauge or connection, etc).
If it's the protocol like it was for me, see if anyone has updated the I2C system library recently and try a different version if possible.
I traced this issue down for days. Luckily I had a number of different MicroPython capable chips and was able to narrow it down to an old version of the machine.I2C library adding that stupid "stop" above.
I bought a $10 protocol analyzer on amazon to make that image above, and I tried loading the code on each of these: Wemos D1, HitLego ESP32S and TTGO T-Display. By trying the code on each, I was able to narrow it down to only the T-Display not working, which needed an custom old firmware version to get the ST7789 display working. The next step is to try to update and recompile the display library from loboris to work with the most recent Micropython firmware. If I make it work, I will reply below.
I really wanted at first an rs232 8-channel relay board that I could command devices to turn on/off with a command string.
All of the ones I found online have the same deficiency in functionality for me: you can't set a subset of relays at the exact time. I can set relay 1 on, and then relay 7 on afterwards, I can set all 8 relays at once, but there is no command structure to pick out the exact leds I would like to turn on/off.
In the past I have dealt with hardware that had a bit-map of the IO pins, and a bit-map of the states and would apply all 8 settings at once. here are some examples:
to set pins 1 and 7 to on and the other pins off (8-bit binary bit-mapping,) send the following byte: in binary: 0100 0001b
to set pins 1,2,3,6 to on and the other pins off (8-bit binary bit-mapping,) send the following byte: in binary: 0010 0111b
I couldn't find any such device to do this so I thought I could make one with a raspberry pi using a simple 8-channel relay board, something like this:
https://www.amazon.com/SainSmart-101-70-102-8-Channel-Relay-Module/dp/B0057OC5WK
but on a Raspberry Pi, I'm running into the same issue: I don't see a way to set the gpio pins as a block command, only individually setting them in a for loop. I looked all morning and can see things like gpioctl, and mmio, but I can't put it all together to a simple proof of concept program on a testboard, any help would be appreciated.
I would really like a solution in C or scripting,
Thanks,
jleslie
Hi I'm wanting to make a HID dj controller with a Ardiuno uno as the core.
I've had some success with using the unojoy usb gamepad project
http://code.google.com/p/unojoy/
I have read elsewhere that the maximum size for a HID report is 64Bytes so I intend to have
48 analogue inputs at 8 bit resolution and 128 binary inputs (48*8)=384+128 =512b or 64B,
Is this many inputs possible/plausible?
Also is there any open source code for some kind of HID device with this great a many inputs? (or similar)
Thank you.
SELF ANSWERED, Yes it is possible, I am struggling to understand how I should write the report descriptor.