Saturday in Eldon's shop

Yesterday, thanks to my friend Eldon WA0UWH I had an opportunity to do a little welding both on steel and aluminum.  I have not done any welding in over 40 years and have only done Oxy-Acetylene and stick arc welding previously.  While I certainly would not hire out as a welder, I did ok for a first attempt.  It was sure fun and appreciate Eldon offering the use of his equipment and expertise.

We then turned our attention to his non-functioning Bus Pirate and were able to determine that the CLK output from the PIC device on his board is in fact non-functional.  The board additionally has firmware self-test code and it indicated a failure of the CLK output as well.  The rest of the circuit checked out.  Eldon is going to order up a new PIC chip from Mouser and I think he will be back in business.

The last project for the afternoon (other than lunch at a local Mexican restaurant that I paid less for both of us to eat lunch that I do for just myself normally) was to lower Eldon's long wire antenna that we put up back in January of 2012.  The line we use to raise it had gotten stuck probably where it had cut into the hemlock tree's branches when we pulled it up in the first place.  After loosening the loop of line to the top of the tree, we wrapped the line around a length of 2x6 and the two of us took an end of the board and walked away from the tree putting increasing pressure on the line until it either broke the line (unlikely) or brought down the branch.  In fact, neither happened as the line finally broke free and we were able to lower the antenna normally.

Eldon then installed a length of plastic tubing over the line and pulled it to the top of the tree where it remained when he pulled the line back down, so hopefully it is providing some protection for both the tree and the line.  It was a bit comical to watch us try to stuff 3/8" line through this 6-8 foot length of plastic tubing just slightly larger inside diameter than the rope outside diameter.  We were able to stuff a wire thru the hose, but only after running water through the hose slick things up a bit.  Pulling the wire back with the rope connected by tape resulted in them parting ways with the rope about 2 feet from the end.  Blue tape hates water and refused to stick to the rope, and now the rope was a bit saturated.  We found some string that we could tie to the rope and still have it all fit in the hose, but were now faced with the problem of how to get the string through the hose to pull the rope back thru.  In the end, the air compressor came to the rescue.  I tied a knot in the end of the string and used an air nozzle to blow it through the hose (after blowing out all the water).

Finally we had success and were able to get the line through the hose and pulled it up to the top of the tree.  Raising the antenna back up, Eldon is back in business.  We still need to do the same thing at the other end of the antenna, but that is a project for another day.

Checking out the DS1307 RTC with Bus Pirate

Today I am checking out the functionality of the DS1307 with Bus Pirate.  I am supplying power and clock from the Bus Pirate board so +5/Gnd, MOSI/CLK are the only required pins.   Here is the setup:

I set Bus Pirate to I2C at 50khz and turned on the power:

HiZ>m
1. HiZ
2. 1-WIRE
3. UART
4. I2C
5. SPI
6. JTAG
7. RAW2WIRE
8. RAW3WIRE
9. PC KEYBOARD
10. LCD
(1) >4
Mode selected
Set speed:
 1. ~5KHz
 2. ~50KHz
 3. ~100KHz
 4. ~400KHz
(1) >2
READY
I2C>W
POWER SUPPLIES ON
I2C>

Now I should be able to search for the device on the I2C bus and it finds the device at 0xD0, 0xD1 as expected, so at least it is responding.

I2C>(1)
Searching 7bit I2C address space.
   Found devices at:
0xD0(0x68 W) 0xD1(0x68 R)
I2C>

Now, I try to read four bytes from the DS1307:

I2C>[0xd1 rrrr]
I2C START BIT
WRITE: 0xD1 ACK
READ: 0x00 ACK
READ: 0x00 ACK
READ: 0x01 ACK
READ: 0x01 NACK
I2C STOP BIT
I2C>

So, it looks like things are working, yay!