I’m trying to interface with my custom SPI slave board. In synchro mode I achieved normal SPI transfer, but in asynchronous mode I couldn’t get SPI read working. The problem looks like this: when I write to SPI in asynchronous mode and wait for a flag from high level IRQ - the transfer passes and I …

Hiya, I’m not sure what you mean by Synchronous and asynchronous SPI. Could you please elaborate a little further. However, in my experience the following is true for a Q2686 running firmware R7.2 & R7.3: The Q2686 has to be the SPI MASTER (i.e. controls the bus at all times) The Q2686 does not …

Sorry. Seems to be bad ground. Now it is OK.

In SPI sample there is a switch from synchronous to async SPI and vice versa. Synchronous SPI waits for every transfer to complete before it proceeds the next program step so it may be easily reseted by watchdog if it is expected to read too much data. Asynchronous transfer is IRQ based and therefo…

At the hardware level the SPI itself is, of course, always synchronous. The “Synchronous” or “Asynchronous” here refers to the operation of the API calls- not the hardware! As already noted: “Synchronous” API calls don’t return until the operation has completed; “Asynchronous” API calls return …

it mostly indicates a problem, but why not? it’s normal to read zero-filled bytes from my accellerometer sometimes. you’ve got chip-select for that don’t you? if chip-select switches to -not-selected- (logic state depends on the spi-mode) communication should reset. if chip-select switches bac…

Hiya, That’s what I thought - I thought blackyblack was referring to the SPI protocol itself - and I had missed something really major… :unamused: Thinking back, I probably should have said ‘full duplex’, rather than ‘bi-directional’. The Q2686 SPI API only seems to support half-duplex communica…

Agreed! :unamused: Note that it doesn’t seem to be just the Q2686 - it seems to be Open-AT in general?

I meant another thing. When data is being read by q2686 it has a meaningful data on input, but what does it have on output? Is it a default behaviour for all SPI slaves? I tried to tie chip select to ground and have not seen any differences. What is chip select behaviour from q2686 side? I manag…

Since Q26 supports Master only, the CS is always generated by the Q26 (or not used at all)

Since Q26 supports Master only, the CS is always generated by the Q26 (or not used at all) chip select is active low. it is generated on the pin that you designated in the adl_busSPISettings_t

SPI again

IoT Modules General wireless topics

awneil June 18, 2010, 10:24am 18

Looks like proper Full-Duplex is still not supported: Can Open-AT do *Full* Duplex SPI yet?

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SPI again

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