MQTT QoS vs TCP

Started by pozz in comp.arch.embedded2 weeks ago 9 replies

I know TCP is able to guarantee the delivery of messages from sender to receiver, without corruption (thanks to checksums), in order and without...

I know TCP is able to guarantee the delivery of messages from sender to receiver, without corruption (thanks to checksums), in order and without duplication (thanks to sequence numbers). So I'm confused when I read something about MQTT QoS. For example, QoS 1 (at least once) uses ack (PUBACK) and retransmissions (with packet ids) to guarantee that the message is delivered at least one t...


Ada-Europe - AEiC 2023 early registration deadline approaching

Started by Dirk Craeynest in comp.arch.embedded3 weeks ago

----------------------------------------------------------------------- UPDATED Call for Participation ...

----------------------------------------------------------------------- UPDATED Call for Participation *** Early registration DEADLINE May 22 *** 27th Ada-Europe International Conference on Reliable Software Technologies (AEiC 2023) 13-16 June 2023, Lisbon, Portugal www.ada-europe...


LPC1788: uart TX interrupt problem

Started by pozz in comp.arch.embedded3 weeks ago 6 replies

This issue is very difficult to understand when you see it, so it's quite impossible to find the solution here in a newsgroup. However, after...

This issue is very difficult to understand when you see it, so it's quite impossible to find the solution here in a newsgroup. However, after scratching my head for long days, I want to try. Maybe some guy here could enlighten me on the right direction. I have a critical issue with a board based on LPC1788, specifically with UART peripheral. The issue is very annoying because it brings ...


Ada-Europe Int.Conf. Reliable Software Technologies, AEiC 2023

Started by Dirk Craeynest in comp.arch.embedded4 weeks ago

----------------------------------------------------------------------- Call for Participation ...

----------------------------------------------------------------------- Call for Participation *** PROGRAM SUMMARY *** 27th Ada-Europe International Conference on Reliable Software Technologies (AEiC 2023) 13-16 June 2023, Lisbon, Portugal www.ada-europe.org/conferenc...


Embedding a Checksum in an Image File

Started by Rick C in comp.arch.embedded4 weeks ago 82 replies

This is a bit of the chicken and egg thing. If you want a embed a checksum in a code module to report the checksum, is there a way of doing this?...

This is a bit of the chicken and egg thing. If you want a embed a checksum in a code module to report the checksum, is there a way of doing this? It's a bit like being your own grandfather, I think. I'm not thinking anything too fancy, like a CRC, but rather a simple modulo N addition, maybe N being 2^16. I keep thinking of using a placeholder, but that doesn't seem to work


UART connection between ATSAMD20 and ATtiny4313

Started by pozz in comp.arch.embedded4 weeks ago 68 replies

I'd like to use async UART to let these MCUs communicate. The protocol will be request-response with the request generated by the SAM MCU. The...

I'd like to use async UART to let these MCUs communicate. The protocol will be request-response with the request generated by the SAM MCU. The baudrate will be 38400bps. I'd like to use internal oscillator of ATtiny4313, while the SAM will use an external 32.768kHz crystal (that is multiplied by internal PLL to reach 48MHz). I'm not sure if this scenario can work well. My concerns are...


PID controller with a limited range of control variable

Started by pozz in comp.arch.embedded1 month ago 1 reply

In one application an AC voltage sourced by a generator is applied to a load as a PWM waveform. The period PER is fixed (for example, 100ms) and...

In one application an AC voltage sourced by a generator is applied to a load as a PWM waveform. The period PER is fixed (for example, 100ms) and the pulse-width PW has a maximum (for example, 20ms). The user can change the voltage peak (and consequently the voltage RMS) by an handle, while the controller manages automatically the PW. The load changes its temperature when the PWM wavefo...


How to snif full-duplex UART protocol between two nodes

Started by pozz in comp.arch.embedded2 months ago 15 replies

Many times I need to snif and log on a file the activity between two nodes that talk over a full-duplex UART (separate TX and RX lines). Just...

Many times I need to snif and log on a file the activity between two nodes that talk over a full-duplex UART (separate TX and RX lines). Just an example, consider a host MCU that talks with a modem through AT commands. It's a half-duplex protocol because the MCU sends the AT command and the modem replies. However the modem is able to send URC messages that can be emitted at any time. ...


SPI Quad Serial Flash: two "quad" modes?

Started by pozz in comp.arch.embedded2 months ago 5 replies

I'm studying datasheet of SST26VF080A. It's a SPI Quad Flash memory in standard 8 pin package. I'm not sure I correctly understood the quad...

I'm studying datasheet of SST26VF080A. It's a SPI Quad Flash memory in standard 8 pin package. I'm not sure I correctly understood the quad mode. It appears to me two quad modes are supported: SPI Quad mode (IOC=1 in Configuration Register) and SQI mode (after sending Enable Quad I/O command). For example, after setting IOC bit in Configuration Register I can use SQOR command (SPI Qu...


Improved display in Google Groups

Started by Rick C in comp.arch.embedded2 months ago 1 reply

I found this browser extension to let you apply formatting codes to any page. It can be used to apply a monospaced font to Google Groups, which...

I found this browser extension to let you apply formatting codes to any page. It can be used to apply a monospaced font to Google Groups, which will help viewing tables and even ASCII art that people post. I had always thought GG stripped excess white space, like tabs, multiple spaces, blank lines. But it seems that's not correct, they are all there, just not shown naturally.


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