From 46b15effa9fe0916dba60e3dc37f1397a6df0ddf Mon Sep 17 00:00:00 2001 From: Werner Almesberger Date: Sun, 29 May 2011 10:37:17 -0300 Subject: [PATCH] prod/doc/: cleanup and clarifications after proofreading --- prod/doc/analysis.hmac | 27 +++++++++++++++++++-------- prod/doc/flash.hmac | 2 +- prod/doc/index.hmac | 12 +++++++----- prod/doc/setup.hmac | 28 +++++++++++++++++----------- prod/doc/test.hmac | 13 ++++++++----- 5 files changed, 52 insertions(+), 30 deletions(-) diff --git a/prod/doc/analysis.hmac b/prod/doc/analysis.hmac index 6d2e382..9fc0fe0 100644 --- a/prod/doc/analysis.hmac +++ b/prod/doc/analysis.hmac @@ -106,7 +106,8 @@ components as shown in this table:

Ground can be accessed at the cover of the crystal. -Note that the fiducials are not connected to ground. +Note that the fiducials, while looking like test points, +are not connected to anything.

This image shows the location of the measurement points:

@@ -131,7 +132,7 @@ components as shown in this table:

Ground can be accessed at the cover of the crystal, at the shield of the USB connector, or at the test point P11. -Note that the fiducials are not connected to ground. +Note that the fiducials are not connected to anything.

This image shows the location of the measurement points:

@@ -144,9 +145,15 @@ This image shows the location of the measurement points:

The precision of the crystal oscillator is crucial for -operation. Anomalies are easy to detect with even a low-cost oscilloscope -and pinpoint specific problems and help to select further analysis steps. -

+operation. Anomalies are easy to detect with even a low-cost oscilloscope. +This can pinpoint specific problems and help to select further analysis steps. + + + + + + + The crystal used in atben and atusb has a nominal tolerance of +/− 15 ppm at 22-28 C. Low-cost oscilloscopes typically have a timing accuracy of @@ -154,8 +161,12 @@ accuracy of measuring the clock output with such an instrument. Full-speed USB only requires an accuracy of +/− 2500 ppm. We can therefore consider all results within a range of +/− 1000 ppm as -sufficient, and perform more precise measurements by other means. This +sufficient for an initial assessment, and perform more precise measurements +by other means. This applies to atben as well as to atusb. +

+IEEE 802.15.4 requires the transceiver frequency to be accurate +within +/− 40 ppm. @@ -197,7 +208,7 @@ the right: The transceiver provides the clock for the microcontroller in atusb. A clock signal is therefore always available. Immediately after reset, -the transceiver generates a 1 MHz clock. When the microcontrolled comes out +the transceiver generates a 1 MHz clock. When the microcontroller comes out of reset, it raises the transceiver's clock output to 8 MHz and then enables USB.

@@ -222,7 +233,7 @@ filter. 0.999-1.001 MHz, ~3.3 VppCheck presence of firmware; check for shorts on SPI signals; check connectivity of SPI signals 7.992-8.008 MHz, ~3.3 VppPerform precision measurement with - atrf-xtal + atrf-xtal (@@@) OtherCheck voltages; check for contamination around crystal

diff --git a/prod/doc/flash.hmac b/prod/doc/flash.hmac index 87eb28e..8f03021 100644 --- a/prod/doc/flash.hmac +++ b/prod/doc/flash.hmac @@ -56,7 +56,7 @@ To flash the boot loader,

-

  • finally, run +
  • finally, cd to ben-wpan/prod/ and run 
         make flash
    diff --git a/prod/doc/index.hmac b/prod/doc/index.hmac index bb2038e..aea8b0b 100644 --- a/prod/doc/index.hmac +++ b/prod/doc/index.hmac @@ -32,8 +32,8 @@ actual testing. The testing serves two purposes:
    1. Ascertain the correctness of the preceding production steps, and -
    2. identify suffering from random production flaws and either discard - them or prepare them for repair. +
    3. identify boards suffering from random production flaws and either + discard them or prepare them for repair.
    The results of testing and fault analysis also provide feedback for the SMT process and steps preceding it. @@ -43,7 +43,7 @@ The following diagram illustrates the workflow:

    Only atusb boards contain firmware and need flashing (which is -a two-step process, see below). The functional tests and further fault +a two-step process, see below). The functional tests and fault analysis are largely the same for atben and atusb.

    Devices accepted for further use can then be packaged for shipping. @@ -69,13 +69,15 @@ Defective devices can be discarded or retained for a deeper analysis. three roles, with the board in its 8:10 card slot changed as the role requires.

    PC
    -
    a device capable of connecting to a Ben via USB, and of hosting an +
    a device running Linux. Capable of connecting to a Ben via USB, and + of hosting an atusb board. In the production process, a PC can perform three different roles:
    1. Host an atusb board acting as DUT
    2. Host an atusb board acting as reference -
    3. Control a Ben via USB (for convenience) +
    4. Control a Ben via USB (for convenience and to coordinate tests + involving a sender and a receiver)
    In this document, we assume that a single PC is used in all three roles, with one USB host port permanently connecting to the diff --git a/prod/doc/setup.hmac b/prod/doc/setup.hmac index bd2b868..67c1061 100644 --- a/prod/doc/setup.hmac +++ b/prod/doc/setup.hmac @@ -37,7 +37,7 @@ and configuration process.
    -For a DUT and reference device role, the ben-wpan utilities +For a DUT and reference device role, the ben-wpan tools and the test scripts have to be installed on the PC. For flashing the atusb application firmware, also dfu-util and the firmware binary are required. @@ -131,8 +131,8 @@ Instructions for building the binary from sources are To simplify accessing the Ben via TCP/IP, its IP address should be -registered in the hosts file on the PC. If the Ben is running OpenWrt, -use the following command: +registered in the /etc/hosts file on the PC. If the Ben is +running OpenWrt, use the following command: 
     echo 192.168.254.101 ben >>/etc/hosts
    @@ -235,7 +235,7 @@ Finally, upload the tools to the Ben and install them under /usr/bin/ with 
    -make HOST=ben install
+make HOST=ben upload
    Where ben is the host name or IP address assigned to the Ben. @@ -248,7 +248,7 @@ Where ben is the host name or IP address assigned to the Ben. The atusb boot loader is flashed using avrdude. A pre-compiled static binary (suitable for OpenWrt and Jlime) can be installed by running -the following two command on the Ben: +the following two commands on the Ben: 
     wget http://downloads.qi-hardware.com/people/werner/wpan/bindist/avrdude-5.10-de72af351f661b538add81cbc9965278a2f8c40c.tar.gz
@@ -282,8 +282,8 @@ Instructions for building the binary from sources are
 
 
    
 
-The configuration setting described in this section are lost on each
-reset or reboot and either need to be entered again. Alternatively,
+The configuration settings described in this section are lost on each
+reset or reboot and need to be entered again. Alternatively,
 a setup script running at boot time can be written.
 
 
@@ -323,6 +323,10 @@ the place of the MMC driver. To disable it, run
 
     echo spi2.0 >/sys/bus/spi/drivers/at86rf230/unbind
 
    
+Note that the above command only has the desired effect if used
+before running any of the user-space tools. If the kernel driver and
+the user-space tools have already clashed over access to the board, the
+driver will not unbind and a reboot is needed.
 
 
 
@@ -354,7 +358,8 @@ in the actual test environment.
 
 Insert a known to be good atben board and run the following
 command directly on the Ben to record the reference value for the
-clock count with an accuracy of about +/−20 ppm:
+clock count with an accuracy of roughly +/−20 ppm:
+
 
     atrf-xtal 1000 >ben.xtal
 
    
@@ -372,7 +377,7 @@ Ben, and if a stable temperature is maintained.
 
 
 
-The signal strength of a DUT is assesses by comparing it with
+The signal strength of a DUT is assessed by comparing it with
 measurements previously obtained in the same setup, with a known to
 be good device taking the role of the DUT. It is therefore necessary
 to establish a reference profile each time the test environment changes,
@@ -391,8 +396,9 @@ make spectrum
    Then place the devices appropriately and press D in the measurement window to use the displayed spectrum as the reference. Multiple spectra -can be merged into the reference, e.g., if environmental conditions cause -significant variations. Spectra included in the reference are shown in blue. +can be merged into the reference, e.g., if unavoidable environmental +variations cause +significant changes. Spectra included in the reference are shown in blue.

    After a obtaining the reference spectrum, press Q to exit. The Makefile will then record the signal strength limits for an atben diff --git a/prod/doc/test.hmac b/prod/doc/test.hmac index 0f05dff..5f44d28 100644 --- a/prod/doc/test.hmac +++ b/prod/doc/test.hmac @@ -29,8 +29,10 @@ the PC, insert the atben board into the Ben, and place both devices at the same location and with the same orientation used when acquiring the signal strength profile.

    -The two devices should be about 1 m apart, with as few metal or watery -objects between or near them as possible. Location and orientation should +The two devices should be about 1 m apart. Their vicinity should be free +from obstructions and items that can reflect or absorb RF signals. Such +items include metal chairs and human bodies. +Location and orientation should be easily reproducible, e.g., by marking the device's edges on the table with tape. Other transmitters in the 2.4 GHz band will interfere with measurements and should be kept as far away and as inactive as possible. @@ -56,7 +58,8 @@ DUT and reference device roles are reversed.

    -The test process is started with +The test process is started from the directory ben-wpan/prod/ +with 
     make ben
    @@ -162,8 +165,8 @@ frequency-dependent anomalies.

    This test depends on numerous external factors, like the exact position and orientation of the two devices with respect to each other, and the -presence of any items that can reflect or absorb RF signals. Such items -include metal chairs and human bodies. Because of the test's sensitivity +presence of obstacles and conductive items (metal, people, etc.). +Because of the test's sensitivity to environmental factors, the operator needs to decide when the result represents a valid measurement and then confirm the result shown.