{"id":52,"date":"2014-10-09T17:38:42","date_gmt":"2014-10-09T06:38:42","guid":{"rendered":"http:\/\/new.radio-active.net.au\/web3\/?page_id=52"},"modified":"2014-10-09T18:08:23","modified_gmt":"2014-10-09T07:08:23","slug":"adding-a-second-port-to-the-pico-packet","status":"publish","type":"page","link":"http:\/\/www.radio-active.net.au\/web3\/Ham\/TNCs\/2ndpico","title":{"rendered":"Adding A Second Port To The Pico Packet"},"content":{"rendered":"

\nAdding a second serial port to the PacComm PicoPacket<\/h1>\n

I don’t know about you, but I think my PicoPacket is a wonder of
\nmodern engineering…. Sure, I think it is a tiny bit too large, but it
\nis several times smaller than most other units on the market. The size
\nreduction is gained from using surface mount parts, and also going away
\nfrom the traditional CPU with external Serial IC, to an IC with integrated
\nSerial Port.<\/p>\n

The Z80 CPU found in most TNC’s has been replaced with a Z180 CPU. This
\nsmall surface mount IC reduces a lot of the complexity of the TNC.<\/p>\n

The photos that follow will lead you through the connection of a Motorola
\nOncore to the PicoPacket. The Motorola Oncore has uses TTL levels so is
\nquite easy to interface. It can connect straight throgh to the second serial
\nport.<\/p>\n

WARNING: DO NOT CONNECT RS-232 LEVEL SIGNALS TO THE SERIAL PORT YOU
\nARE ABOUT TO ADD.
\n
 
\n
 
\n
 <\/p>\n

\n\n\n
\"\"<\/td>\n<\/tr>\n
This is the underside of the PicoPacket. The upper
\nright corner is the location of SP21 and the second serial port connection.<\/caption>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n
\"\"<\/td>\n<\/tr>\n
PicoPacket PCB showing the location of SP21. Note
\nthat the bridge between pins 1 & 2 have been cut, and pins 2 &
\n3 have been joined by solder. Directly above SP21 is J1 where connections
\nto the second serial port are made.<\/caption>\n<\/table>\n<\/div>\n
\n\n\n\n\n\n
J1 Pinouts<\/caption>\n
Pin 1<\/td>\n5 Volts (or higher depending on SP21)<\/td>\n<\/tr>\n
Pin 2<\/td>\nReceived Data – TTL Level<\/td>\n<\/tr>\n
Pin 3<\/td>\nGround<\/td>\n<\/tr>\n
Pin 4<\/td>\nTransmit Data – TTL Level<\/td>\n<\/tr>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n
\"\"<\/td>\n<\/tr>\n
This is the top of my PicoPacket showing how I mounted
\nthe header and wired it to the ribon cable. I is not pretty but it works.<\/caption>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n
\"\"<\/td>\n<\/tr>\n
This is the back of my PicoPacket. Ignore the hole
\nin the middle of the FCC statement. That was a mistake. The MiniCannon
\nsocket is mounted just above the ON\/OFF switch. It is held in location
\nby being a tight fit, and also a cable tie at the back.<\/caption>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n
\"\"<\/td>\n<\/tr>\n
A closer view of the socket and switch<\/caption>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n
\"\"<\/td>\n<\/tr>\n
This is a picture of the 4 pin micro-cannon plug,
\nsimilar to, but much smaller than the ones used on microphones in professional
\nrecording.<\/caption>\n<\/table>\n<\/div>\n

 
\n
 <\/p>\n

\n\n\n
\"\"<\/td>\n<\/tr>\n
This is a view of the Motorola Oncore GPS in the
\nHorwood Aluminiumn case. The BNC socket on the front is for the GPS antenna.<\/caption>\n<\/table>\n<\/div>\n

 <\/p>\n

\n\n\n
\"\"<\/td>\n<\/tr>\n
Looking at more detail towards the back of the case.
\nI used a 3.5mm socket as a ferule. Ignore the white electrical tape. I
\nmade a mistake when I was wiring up and needed to make a minor modification.
\nThe ribbon cable is terminated on a piece of matrix board with a row of
\nheaders attached. The GPS was screwed to the bottom of the case.<\/caption>\n<\/table>\n<\/div>\n

 <\/p>\n

Once you have wired everything together, you can test the setup. The
\nfirst test is to monitor the data stream coming from the GPS with a CRO.
\nIf it looks good you are almost assured of success. Now we need to set
\nup the TNC<\/p>\n

Go into the command mode of the TNC and type<\/p>\n

            GPS
\nOFF<\/p>\n

This will disable GPS from the external serial port and force data from
\nthe new second serial port.<\/p>\n

        BAUD<\/p>\n

Follow the instructions to set the GPS bit rate. This will normally
\nbe 4800 bps.<\/p>\n

Once set, pressing CTRL-E or CTRL-D will often bring up the data from
\nthe GPS. If someone wans to write a bit more here, please let me know.<\/p>\n

For more information contact me<\/p>\n

\n","protected":false},"excerpt":{"rendered":"

Adding a second serial port to the PacComm PicoPacket I don’t know about you, but I think my PicoPacket is a wonder of modern engineering…. Sure, I think it is a tiny bit too large, but it is several times …<\/p>\n

Adding A Second Port To The Pico Packet<\/span> Read More »<\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"parent":50,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"jetpack_post_was_ever_published":false,"footnotes":""},"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/P5cfmK-Q","_links":{"self":[{"href":"http:\/\/www.radio-active.net.au\/web3\/wp-json\/wp\/v2\/pages\/52"}],"collection":[{"href":"http:\/\/www.radio-active.net.au\/web3\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/www.radio-active.net.au\/web3\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/www.radio-active.net.au\/web3\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"http:\/\/www.radio-active.net.au\/web3\/wp-json\/wp\/v2\/comments?post=52"}],"version-history":[{"count":2,"href":"http:\/\/www.radio-active.net.au\/web3\/wp-json\/wp\/v2\/pages\/52\/revisions"}],"predecessor-version":[{"id":76,"href":"http:\/\/www.radio-active.net.au\/web3\/wp-json\/wp\/v2\/pages\/52\/revisions\/76"}],"up":[{"embeddable":true,"href":"http:\/\/www.radio-active.net.au\/web3\/wp-json\/wp\/v2\/pages\/50"}],"wp:attachment":[{"href":"http:\/\/www.radio-active.net.au\/web3\/wp-json\/wp\/v2\/media?parent=52"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}