Root/TODO

Source at commit 33926475741878e548c670f24284ed1b87a24954 created 8 years 10 months ago.
By Werner Almesberger, great atusd -> atben renaming: changed the directory name
1General
2=======
3
4Things not done yet
5-------------------
6
7- document directory hierarchy
8
9- make sure all files have a copyright header or are listed in AUTHORS
10
11- connect all the bits and pieces of the build system
12
13- combine io-parts.h generation
14
15- combine "standard" EP0 commands, such as *_ID and *_BUILD
16
17- implement return to DFU in application's EP0 protocol
18
19- consider removing *_ID and using bcdDevice instead
20
21
22Bugs to fix
23-----------
24
25- builds fail if .version isn't there yet
26
27
28
29atrf
30====
31
32AT86RF230-based IEEE 802.15.4 transceiver. Two variants: one to make a USB
33dongle for use with any Linux host, and one that connects with SPI directly
34inside a Ben.
35
36Update: following Rikard Lindstrom's revelation that we can use the uSD slot
37also just as general GPIOs, the variant that goes inside the Ben can wait a
38bit and the atusd board for insertion into the uSD slot is being worked on
39first. We can verify most of the design of a fully integrated board with the
40atusd board and the latter will be of greater immediate use.
41
42
43Things done
44-----------
45
46- verify that the Ben can output an a) 16 MHz clock, and b) with +/- 40 ppm
47
48  Done, see ecn/ecn0005.txt. Works fine.
49
50- replace discrete balun and filter with integrated solution, to reduce BOM
51  size, maybe cost, insertion loss, and PCB space (see ATRF/ECN0003)
52
53  Done for atusd. At a first glamce, does not seem to affect performance.
54
55- check if we really need three DC blocking caps in the RF path
56
57  Reduced to two in atusd without apparent ill effects.
58
59
60Things not done yet
61-------------------
62
63- examine spectrum around carrier frequency and first harmonic to look for
64  obvious distortions. Vary transmit power.
65
66- measure throughput as a function of placement/distance, carrier frequency,
67  and transmit power
68
69- atrf-txrx: suppport "extended mode" with IEEE 802.15.4 CSMA-CA for more
70  realistic throughput figures
71
72- measure full spectrum (ideally up to 25 GHz, but just 2nd and 3rd harmonic
73  will already tell most of the story) with calibrated antenna for FCC/ETSI
74  compliance assessment. Vary transmit power.
75
76- use IEEE 802.15.4 stack from linux-zigbee. The linux-zigbee kernel is
77  currently at 2.6.35. Once 2.6.36 is released, we should have Ben and
78  IEEE 802.15.4 support in the same kernel without further ado.
79
80- change layout of transceiver side of the board for placement inside Ben
81
82- define EMI filters for placement inside Ben
83
84- check USB standard for recommended USB dongle dimensions
85
86- change layout for straight USB dongle
87
88- generate proper BOM
89
90- implement sleep mode
91
92- (atusd) verify SPI signal timing, particularly the data clock
93
94
95ccrf
96====
97
98Board similar to the atrf, but with the TI/Chipcon CC2520.
99
100Cancelled. The CC2520 falls under US export restrictions, apparently because
101it contains an AES engine.
102
103
104cntr
105====
106
107Simple USB-based counter to measure a clock's long-time accuracy with
108arbitrarily high precision, by comparing it to an NTP time reference.
109
110
111Things not done yet
112-------------------
113
114- measure duty cycle
115
116- use the LED to display activity on clock input and duty cycle
117
118- consider using a comparator and a DAC to allow for programmable logic levels
119
120- evaluate termination resistance
121
122- document circuit design
123
124- record beats between 16 bit counter polls and use them for the estimate
125  of lost cycles (2*1 is way too optimistic)
126
127- include system clock resolution in accuracy calculation
128
129- consider running shorter sliding windows to estimate drift
130
131- consider detecting unusual half-periods
132
133- consider using a reversed USB connector, to avoid having to cross D+/D- and,
134  worse, VBUS and GND
135
136- test input performance by counting a source that emits a known number of
137  cycles
138
139- consider using historical margins to sanity-check the current margin (if any
140  old.max < curr.min or old.min > curr.max, we have a problem) and to further
141  narrow the effective margin, thus achieving faster convergence. We would have
142  to consider temperature drift of the frequency source in this case.
143
144- find out why frequency measurements always seem to start high and then slowly
145  drop
146

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