Atmega644P Second Serial port

Using Arduino Microcontrollers
1

I am using a ATmega644P and would like have a second serial port.
The device has one but I can not see how to "use" it. (Pins 16 = RX1, pin 17 = TX1)

Have used "softserial" but while the Tx works on the 644, the Rx on ANY pin I program does not?
I have used softserial on my Duemilanove and it works, I just ran out of program space, so migrated to the 644.
I am using Sanguino 644 8MHz for the "Board"
Can any one advice pls.

Also can some point me to a "table" that lists what the letters mean after the ATmega chips, P/PU/V/A etc

Thanks

2

does serial1 work (keeping in mind the first port is Serial0)

for instance

Serial1.read()

3

Osgeld:
does serial1 work (keeping in mind the first port is Serial0)

for instance

Serial1.read()

I recall testing the serial1 port on my 644P when I got the board first working and the second serial port worked with my simple tests.

Keep in mind that the 644 non-P model does not contain the second hardware serial port.

Lefty

4

"Also can some point me to a "table" that lists what the letters mean after the ATmega chips, P/PU/V/A etc"
That can be found in the datasheets.
In general, the first part:
Atmega644, 644A, 644P, 644PA,
The P stands for Pico power, while the A refers to an update,
and -PU, -AU, -MU, etc. refers to the packaging. DIP, quad flat pack, leadless, ball grid array, etc.

...select "microcontroller selector" for a parametric kind of search....

...or, try this one...
AVR Product Finder

...or, for those with a mobile phone...

http://www.atmel.com/v2PFResults.aspx#(actives:!(8238,8394,8362,8282,8431,8300,8358,8392,8378,8445,8236,8449,8474,8248,8264,8447,8256,8254,8286,8462,8429,8458,8466,8400,8302,8278),data:(area:'',category:'34864[33180[33085]]',pm:!((i:8238,v:!(4,14)),(i:8394,v:!(4,12)),(i:8362,v:!(5,6)),(i:8282,v:!(1)),(i:8431,v:!(5,22)),(i:8300,v:!(4,8)),(i:8358,v:!(10,47)),(i:8392,v:!(0,1)),(i:8378,v:!n),(i:8445,v:!(4,5,8)),(i:8236,v:!(7,12)),(i:8449,v:!(1,6)),(i:8474,v:!(0)),(i:8248,v:!(0,1)),(i:8264,v:!(1,4)),(i:8447,v:!(0,1)),(i:8256,v:!(1)),(i:8254,v:!(6,11)),(i:8286,v:!(0,1)),(i:8462,v:!(0,4)),(i:8429,v:!(1,5)),(i:8458,v:!(0,1)),(i:8466,v:!(1,2,4)),(i:8400,v:!(2,12)),(i:8278,v:!(1))),view:table),sc:1)

Edit: re-updated the link :smiley:

5

That second link is ugly looking and doesn't work.

Lefty

6

Updated the link.

7

Hi
Thanks for the all your prompt reply's.
"Serial1".worked, but funny enough when I use "Serial0". it does not compile...
But "Serial." does, thanks anyway, system working, so I can move on.
"Letters" after chip number, thanks for the list.
Not sure about if "no 2nd serial" if P is missing thou.....

Best regards

8

Yes, Serial, Serial1, and for Mega, Serial2, Serial3.

Atmega644: only 1 UART

Atmega644A: 2 UART

Atmega644P: 2 UART

Atmega644PA: 2 UART

9

I thought I remember reading somewhere that the reference to no second serial port on the non-P 644 was an error and it does in fact have a second UART.

I keep meaning to get my 644P's and 644's bootloaded and actually prove it true or false, unless someone else can confirm.

10

tack:
I thought I remember reading somewhere that the reference to no second serial port on the non-P 644 was an error and it does in fact have a second UART.

I keep meaning to get my 644P's and 644's bootloaded and actually prove it true or false.

The Atmel datasheets are pretty clear on the matter. From the 644 datasheet:

The ATmega644 has one USART, USART0.

I've got a optiboot version hex file that works on the 644 chip:

optiboot_atmega644p-4-5.hex

:020000000504F5
:10FC0000112484B714BE81FFF2D085E08093810077
:10FC100082E08093C00088E18093C10086E08093F9
:10FC2000C20080E18093C4008EE0CBD0209A86E0B1
:10FC300020E33CEF91E0309385002093840096BB55
:10FC4000B09BFECF189AA8958150A9F7CC24DD244B
:10FC500088248394B5E0AB2EA1E19A2EF3E0BF2E69
:10FC6000A4D0813471F4A1D0082FB1D0023811F49E
:10FC700085E005C0013811F484E001C083E08DD037
:10FC800089C0823411F484E103C0853419F485E01D
:10FC9000A6D080C0853579F488D0E82EFF2485D0A1
:10FCA000082F10E0102F00270E291F29000F111F09
:10FCB0008ED068016FC0863521F484E090D080E05A
:10FCC000DECF843609F040C070D06FD0082F6DD0E1
:10FCD00080E0C81680EED80618F4F601B7BEE895A5
:10FCE000C0E0D1E062D089930C17E1F7F0E0CF16C5
:10FCF000F0EEDF0618F0F601B7BEE89568D007B65B
:10FD000000FCFDCFA601A0E0B1E02C9130E01196FF
:10FD10008C91119790E0982F8827822B932B129625
:10FD2000FA010C0187BEE89511244E5F5F4FF2E0A7
:10FD3000A030BF0751F7F601A7BEE89507B600FC53
:10FD4000FDCF97BEE89526C08437B1F42ED02DD0D4
:10FD5000F82E2BD03CD0F601EF2C8F010F5F1F4FF8
:10FD600084911BD0EA94F801C1F70894C11CD11CFE
:10FD7000FA94CF0CD11C0EC0853739F428D08EE10F
:10FD80000CD086E90AD08AE07ACF813511F488E078
:10FD900018D01DD080E101D063CF982F8091C00092
:10FDA00085FFFCCF9093C60008958091C00087FF27
:10FDB000FCCF8091C00084FD01C0A8958091C60051
:10FDC0000895E0E6F0E098E1908380830895EDDF08
:10FDD000803219F088E0F5DFFFCF84E1DECF1F939A
:10FDE000182FE3DF1150E9F7F2DF1F91089580E04B
:08FDF000E8DFEE27FF2709946C
:040000030000FC00FD
:00000001FF

And the boards.txt entry to add a 644P with optiboot support:

##############################################################


bobuino644.name=Bobuino 644P optiboot
bobuino644.upload.protocol=arduino
bobuino644.upload.maximum_size=63488
bobuino644.upload.speed=115200
bobuino644.bootloader.low_fuses=0xff
bobuino644.bootloader.high_fuses=0xdc
bobuino644.bootloader.extended_fuses=0xfd
bobuino644.bootloader.path=optiboot
bobuino644.bootloader.file=optiboot_atmega644p-4-5.hex
bobuino644.bootloader.unlock_bits=0x3F
bobuino644.bootloader.lock_bits=0x0F
bobuino644.build.mcu=atmega644p
bobuino644.build.f_cpu=16000000L
#bobuino644.build.core=arduino:arduino
bobuino644.build.core=standard
bobuino644.build.variant=bobuino

##############################################################

Lefty

11

jamesvote:
I am using a ATmega644P and would like have a second serial port.
The device has one but I can not see how to "use" it. (Pins 16 = RX1, pin 17 = TX1)

Have used "softserial" but while the Tx works on the 644, the Rx on ANY pin I program does not?
I have used softserial on my Duemilanove and it works, I just ran out of program space, so migrated to the 644.
I am using Sanguino 644 8MHz for the "Board"
Can any one advice pls.

Also can some point me to a "table" that lists what the letters mean after the ATmega chips, P/PU/V/A etc

Thanks

I have the same problem I need to use 3 serial ports, so in addition with Serial1 and serial0(Serial) i have to use a third one with softwareserial.h when Tx work perfectly Rx does not work on any pin.

12

Hi,

Has anyone found a solution to use 3 serial ports ?

I'm trying to use 2 hardware serial and 1 software serial but unsuccessful :frowning:

My Atmega644P@Ext8MHz can send data but can't receive..

Please HELPPP!!

13

My Atmega644P@Ext8MHz can send data but can't receive..

I have no experience with the 644p but I've using the 1284p and faced a similar problem in the past and I too was unable to receive on SoftwareSerial port. (The 1284p has a second hardware serial port but still I needed two more!)

The problem was solved after I switched to the Mighty Core and at the same time to the latest IDE 1.8.x leaving behind the 1.06. I am now using pins PB0 & PC4 for the receive pins of two SoftwareSerial ports. (Can only receive from one port at a time though)

I hope the above helps!

14

@nk36 :Do let us know if you managed to solve your problem...