I2C read from 16bit register address

Toit

#I2C read from 16bit register address

Thread channel in help

theHuanter 04/03/2024 01:09 PM

I want to implement the driver for the VL53L4CD ToF Sensor - I did this already in the past and somehow they have larger register addresses then usual.
For example the register of the device ID is 0x010F but if I try to read it with toit I get the following error

******************************************************************************
Decoding by `jag`, device has version <2.0.0-alpha.143>
******************************************************************************
EXCEPTION error.
INVALID_ARGUMENT
  0: i2c-read-reg_             <sdk>\i2c.toit:314:3
  1: Bus.read-reg_             <sdk>\i2c.toit:115:10
  2: Device.read-reg           <sdk>\i2c.toit:242:17
  3: Device.read-reg           <sdk>\i2c.toit:235:12
  4: Registers.read-bytes      <sdk>\i2c.toit:291:20
  5: Registers.read-u16-be     <sdk>\serial\registers.toit:83:14
  6: VL53L4CD-DRIVER.get-identification-model-id toit\vl53l4cd-driver.toit:25:22
  7: VL53L4CD.get-id           toit\vl53l4cd.toit:26:20
  8: main                      toit\examples\05-vl534cd.toit:23:29
******************************************************************************

Is there a way of setting this address or still get to read this vlaue somehow using whats implemented in toit already?

OPtheHuanter

I want to implement the driver for the VL53L4CD ToF Sensor - I did this already in the past and somehow they have larger register addresses then usual. For example the register of...

floitsch 04/03/2024 01:22 PM

I'm pretty sure Toit supports 16 bit addresses. Maybe not through read-reg, though. Let me check.

floitsch 04/03/2024 01:23 PM

Try device.read-address #[0x01, 0x0F] <length>

theHuanter 04/03/2024 01:25 PM

that seems to work

theHuanter 04/03/2024 01:28 PM

can I "cast" this IDENTIFICATION_MODEL_ID ::= 0x010F into an ByteArray or do I have to change this constants into ByteArrays? Whats better?

erikcorry 04/03/2024 01:43 PM

Perhaps

cast value/int -> ByteArray
  return #[value >> 8, value]

(edited)

OPtheHuanter

I want to implement the driver for the VL53L4CD ToF Sensor - I did this already in the past and somehow they have larger register addresses then usual. For example the register of...

RaspPi Parts 04/04/2024 08:15 AM

Friend, I2C address is either 7 bit or 10 bit. There is no 16 bit I2C address. Please check Philips/NXP documents. either 0x7F or 0x3FF. Your device ID is 0x10F 10 bit address.(edited)

RaspPi Parts

Friend, I2C address is either 7 bit or 10 bit. There is no 16 bit I2C address. Please check Philips/NXP documents. either 0x7F or 0x3FF. Your device ID is 0x10F 10 bit address.(edited)

floitsch 04/04/2024 08:18 AM

Register addresses can be off different sizes, though.
Since accessing registers is a common operation Toit has a direct function for it. However, the read-reg function only takes 8-bit addresses. For accessing registers with 16 (or more) bits one needs to use read-address.

RaspPi Parts

Friend, I2C address is either 7 bit or 10 bit. There is no 16 bit I2C address. Please check Philips/NXP documents. either 0x7F or 0x3FF. Your device ID is 0x10F 10 bit address.(edited)

theHuanter 04/04/2024 08:37 AM

thats true for the I2C Address - but I am talking about the register address to read or write to a specific register of a device with its 7 or 10 bit address.

floitsch

Register addresses can be off different sizes, though. Since accessing registers is a common operation Toit has a direct function for it. However, the read-reg function only take...

theHuanter 04/04/2024 08:38 AM

is there an equivalent in toit for this micropython struct https://docs.micropython.org/en/latest/library/struct.html ?

theHuanter 04/04/2024 08:39 AM

I wrote my own now but I was wondering if there might be something like that already

import binary show LITTLE-ENDIAN BIG-ENDIAN

pack-16 value -> ByteArray:
  buffer := ByteArray 2
  BIG-ENDIAN.put-uint16 buffer 0 value
  return buffer

unpack-16 buffer/ByteArray:
  return BIG-ENDIAN.uint16 buffer 0

pack-32 value -> ByteArray:
  buffer := ByteArray 4
  BIG-ENDIAN.put-uint32 buffer 0 value
  return buffer

unpack-32 buffer/ByteArray:
  return BIG-ENDIAN.uint32 buffer 0

OPtheHuanter

is there an equivalent in toit for this micropython struct https://docs.micropython.org/en/latest/library/struct.html ?

floitsch 04/04/2024 09:32 AM

Not yet.
We have a proposal for "byte classes", but so far we haven't had the time to experiment with/implement it: https://docs.google.com/document/d/1QGW0IJUojA2Wq0oeo7EC15pURMJNnY3kvxGanr9Z3-Y/edit

Byte Classes

12 messages in total