From 9b7d4b4394e3405a447932eb1aaa646f70c7b59d Mon Sep 17 00:00:00 2001 From: Josh Blum Date: Wed, 4 Aug 2010 12:10:23 -0700 Subject: dbsrx: modification docs --- host/docs/dboards.rst | 43 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-) (limited to 'host/docs') diff --git a/host/docs/dboards.rst b/host/docs/dboards.rst index 8e6ecc4ae..b66fd2069 100644 --- a/host/docs/dboards.rst +++ b/host/docs/dboards.rst @@ -32,7 +32,7 @@ The Basic TX and LFTX boards have 1 quadrature subdevice using both antennas. The boards have no tunable elements or programmable gains. Though the magic of aliasing, you can up-convert signals -greater than the nyquist rate of the DAC. +greater than the Nyquist rate of the DAC. ^^^^^^^^^^^^^^^^^^^^^^^^^^^ DBSRX @@ -100,3 +100,44 @@ the receive antenna will always be set to RX2, regardless of the settings. Transmit Gains: **PGA0**, Range: 0-25dB Recieve Gains: **PGA0**, Range: 0-31.5dB + +------------------------------------------------------------------------ +Daughterboard Modifications +------------------------------------------------------------------------ + +Sometimes, daughterboards will require modification +to work on certain frequencies or to work with certain hardware. +Modification usually involves moving/removing a SMT component +and burning a new daughterboard id into the eeprom. + +^^^^^^^^^^^^^^^^^^^^^^^^^^^ +DBSRX +^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Due to different clocking capabilities, +the DBSRX will require modifications to operate on a non-USRP1 motherboard. +On a USRP1 motherboard, a divided clock is provided from an FPGA pin +because the standard daughterboard clock lines cannot provided a divided clock. +However, on other USRP motherboards, the divided clock is provided +over the standard daughterboard clock lines. + +**Step 1: Move the clock configuration resistor** + +Remove R193 (which is 10 ohms, 0603 size) and put it on R194, which is empty. +This is made somewhat more complicated by the fact that the silkscreen is not clear in that area. +R193 is on the back, immediately below the large beige connector, J2. +R194 is just below, and to the left of R193. +The silkscreen for R193 is ok, but for R194, +it is upside down, and partially cut off. +If you lose R193, you can use anything from 0 to 10 ohms there. + +**Step 2: Burn a new daughterboard id into the EEPROM** + +With the daughterboard plugged-in, run the following commands: +:: + + cd /share/uhd/utils + ./usrp_burn_db_eeprom --id=0x000d --unit=RX --args= --db= + +* are device address arguments (optional if only one USRP is on your machine) +* is the name of the daughterboard slot (optional if the USRP has only one slot) -- cgit v1.2.3