Root/TODO

Source at commit 85f60de9d52195afb3a0232a03e850d96584bb9a created 8 years 7 months ago.
By Werner Almesberger, atusb/fw: use the unique serial number of the ATmega8/16/32U2 for iSerialNumber
1*** NEEDS UPDATING ***
2
3General
4=======
5
6Things not done yet
7-------------------
8
9- document directory hierarchy
10
11- make sure all files have a copyright header or are listed in AUTHORS
12
13- connect all the bits and pieces of the build system
14
15- combine io-parts.h generation
16
17- combine "standard" EP0 commands, such as *_ID and *_BUILD
18
19- implement return to DFU in application's EP0 protocol
20
21- consider removing *_ID and using bcdDevice instead
22
23
24Bugs to fix
25-----------
26
27- builds fail if .version isn't there yet
28
29
30
31atrf
32====
33
34AT86RF230-based IEEE 802.15.4 transceiver. Two variants: one to make a USB
35dongle for use with any Linux host, and one that connects with SPI directly
36inside a Ben.
37
38Update: following Rikard Lindstrom's revelation that we can use the uSD slot
39also just as general GPIOs, the variant that goes inside the Ben can wait a
40bit and the atben board for insertion into the uSD slot is being worked on
41first. We can verify most of the design of a fully integrated board with the
42atben board and the latter will be of greater immediate use.
43
44
45Things done
46-----------
47
48- verify that the Ben can output an a) 16 MHz clock, and b) with +/- 40 ppm
49
50  Done, see ecn/ecn0005.txt. Works fine.
51
52- replace discrete balun and filter with integrated solution, to reduce BOM
53  size, maybe cost, insertion loss, and PCB space (see ATRF/ECN0003)
54
55  Done for atben. At a first glamce, does not seem to affect performance.
56
57- check if we really need three DC blocking caps in the RF path
58
59  Reduced to two in atben without apparent ill effects.
60
61
62Things not done yet
63-------------------
64
65- examine spectrum around carrier frequency and first harmonic to look for
66  obvious distortions. Vary transmit power.
67
68- measure throughput as a function of placement/distance, carrier frequency,
69  and transmit power
70
71- atrf-txrx: suppport "extended mode" with IEEE 802.15.4 CSMA-CA for more
72  realistic throughput figures
73
74- measure full spectrum (ideally up to 25 GHz, but just 2nd and 3rd harmonic
75  will already tell most of the story) with calibrated antenna for FCC/ETSI
76  compliance assessment. Vary transmit power.
77
78- use IEEE 802.15.4 stack from linux-zigbee. The linux-zigbee kernel is
79  currently at 2.6.35. Once 2.6.36 is released, we should have Ben and
80  IEEE 802.15.4 support in the same kernel without further ado.
81
82- change layout of transceiver side of the board for placement inside Ben
83
84- define EMI filters for placement inside Ben
85
86- check USB standard for recommended USB dongle dimensions
87
88- change layout for straight USB dongle
89
90- generate proper BOM
91
92- implement sleep mode
93
94- (atben) verify SPI signal timing, particularly the data clock
95
96
97ccrf
98====
99
100Board similar to the atrf, but with the TI/Chipcon CC2520.
101
102Cancelled. The CC2520 falls under US export restrictions, apparently because
103it contains an AES engine.
104
105
106cntr
107====
108
109Simple USB-based counter to measure a clock's long-time accuracy with
110arbitrarily high precision, by comparing it to an NTP time reference.
111
112
113Things not done yet
114-------------------
115
116- measure duty cycle
117
118- use the LED to display activity on clock input and duty cycle
119
120- consider using a comparator and a DAC to allow for programmable logic levels
121
122- evaluate termination resistance
123
124- document circuit design
125
126- record beats between 16 bit counter polls and use them for the estimate
127  of lost cycles (2*1 is way too optimistic)
128
129- include system clock resolution in accuracy calculation
130
131- consider running shorter sliding windows to estimate drift
132
133- consider detecting unusual half-periods
134
135- consider using a reversed USB connector, to avoid having to cross D+/D- and,
136  worse, VBUS and GND
137
138- test input performance by counting a source that emits a known number of
139  cycles
140
141- consider using historical margins to sanity-check the current margin (if any
142  old.max < curr.min or old.min > curr.max, we have a problem) and to further
143  narrow the effective margin, thus achieving faster convergence. We would have
144  to consider temperature drift of the frequency source in this case.
145
146- find out why frequency measurements always seem to start high and then slowly
147  drop
148

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