I know what RS485 is used for - the issue I initially raised is the code at the Arduino site is specific to the RS485 add on card and will not work with the serial port without modifications. John later provided a link to the modbus implementation he had used that was configured fo serial port use.
On Tue, Oct 27, 2020 at 3:37 PM Scott Hall via TriEmbed < [email protected]> wrote: > Modbus can be used over a TTL serial link -- as long as you take > electrical characteristics into consideration. In fact, modbus has been > used in many connection types, even parallel buses and wireless links. > I've even seen modbus embedded in another protocol layer, such as Zigbee, > MQTT or of course TCP. A RS485 link requires a balancing circuit or > transformers at either end and is really designed for long or multidevice > signaling, and not needed for short wire or direct bus connections in close > proximity. > > - sgh > > On 10/26/20 10:23 AM, Rodney Radford via TriEmbed wrote: > > I have not used the modbus Arduino code before, but it does look > interesting. However in reading the description they state it is designed > to use with either their Ethernet shield or the RS485 shield, but I did not > see anything on running it with just a standalone Arduino. If it is > possible to just use the TTL serial port of the Arduino, that would be very > nice, indeed. > > On Mon, Oct 26, 2020 at 8:20 AM John Vaughters via TriEmbed < > [email protected]> wrote: > >> >You might avoid the ADC chip and instead use an Arduino. >> >> +1 >> >> My favorite combo is to use the Rpi UART with a nano arduino that has 8 >> ADCs @ 10bit and you can get them for like $5. I like to make the ardiuno >> dumb with a modbus slave. The combination with the UART/MODBUS is extremely >> reliable. You can also pump it out to tcp with the mbusd utility. >> >> Just some thoughts >> >> John Vaughters >> >> On Monday, October 26, 2020, 7:14:39 AM EDT, John Moore via TriEmbed < >> [email protected]> wrote: >> >> You might avoid the ADC chip and instead use an Arduino. Some Arduino's >> give an 8 channel ADC at 10 bits resolution. >> https://www.arduino.cc/en/Tutorial/Foundations/AnalogInputPins >> >> -John Moore >> >> On Sun, Oct 25, 2020 at 10:34 AM The MacDougals via TriEmbed < >> [email protected]> wrote: >> >> I am looking for an 8 channel ADC chip. >> 10 bit is sufficient. I2C is preferred but SPI would be OK. >> Hand solderable package highly preferred. >> I found these: >> https://www.ti.com/lit/ds/symlink/adc128d818.pdf - $5.30 at DigiKey >> >> https://www.analog.com/media/en/technical-documentation/data-sheets/2309fd.pdf >> - $7.34 at Digikey >> >> Any opinions? Anyone have something in their personal stock? >> Anyone interested in sharing shipping costs on a DigiKey order? >> >> ---> Paul >> >> >> > _______________________________________________ > Triangle, NC Embedded Computing mailing list > > To post message: [email protected] > List info: http://mail.triembed.org/mailman/listinfo/triembed_triembed.org > TriEmbed web site: http://TriEmbed.org > To unsubscribe, click link and send a blank message: mailto: > [email protected]?subject=unsubscribe > >
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