[Cyborg] Fwd: [Noisebridge-discuss] Re: March Digikey Bulk Order

Lamont Lucas lamont at cluepon.com
Mon Mar 23 13:52:24 PDT 2009


Page 4 of the datasheet shows the broken down diagram, with the 
measurement I'm calling "spacing" being lowercase e, the center-of-pin 
to center-of-pin measurement.  That's the one that I can't find an 
off-the-shelf adapter for, since everybody else seems to think that 
PLCC-20 is 0.05" between center-of-pin, or 1.27mm.

Since honeywell includes a photo as you pointed out, it's not a typo in 
the datasheet and I'm left with nothing but making a custom PCB, unless 
someone has better google skills than me. 

If we order the chip first, it's helpful to lay the chip on a laser 
printed paper version of the board to make sure the pins all line up.  
And I'll probably laser cut a stencil at TechShop to make the soldering 
easier.

Rachel McConnell wrote:
> That compass board is 4mm across.  There are 5 pads.  The pic on the
> datasheet shows the pads right up next to a mm ruler, and in fact
> further down it claims the distance across all the pads & the spaces
> between is 2.5mm.  Given that, I don't see how the spacing could be as
> big as .5mm but it is absolutely not any larger.
>
> However, 0.05" is a lot bigger than 0.5 mm so if those are the only 2
> options, I am baffled.  Or possibly just even more ignorant about what
> 'spacing' means than I thought.
>
> R
>
> Lamont Lucas wrote:
>   
>> Oh, and cause I like replying to myself, here's another board adapter
>> that I thought would allow us to mount the chip with just a fine point
>> iron:
>>
>> http://www.schmartboard.com/index.asp?page=products_plcc&id=85
>>
>> $9, but I think it's the wrong board.
>>
>> it *says* PLCC-20, but the pin spacing is 0.05", (1.27mm) whereas we
>> need 0.5 mm spacing according to the datasheet for the HMC5843.  I'm
>> starting to wonder if the datasheet is wrong, as every other source I've
>> found says 0.05" for the PLCC, but honeywell claims 0.5mm.
>>
>> The other PLCC-20 smt adapter board that I have also has an incorrect
>> pin spacing in inches, so I'm left wondering what the hell honeywell is
>> doing, seeing as what they're calling PLCC has nothing to do with what
>> the rest of the world does.  (PLCC, plastic leadless chip carrier)
>>
>> I'll try and make an adapter board in eagleCAD tonight and submit it for
>> folks' inspection.
>>
>> Finally, here's someone on sparkfun trying to use the chip with no love:
>>
>> http://forum.sparkfun.com/viewtopic.php?p=68979#68979
>>
>> I'll hopefully get a response back from him, as he's successfully
>> mounted the chip, even if he can't use it correctly.
>>
>> Lamont Lucas wrote:
>>     
>>> Please add one more to the order for me, and I'll work with you on
>>> surface mounting the thing.  I have a hot-air rework station that will
>>> be useful for undoing whatever we mess up.  I've used a toaster oven
>>> for SMT reflow, but I'd like to do this with a regular hot-plate, as I
>>> think that method is superior.
>>>
>>> We'll need to either order an adapter PCB for the PLLC-20 (aka
>>> LPCC-20), or make a custom one.  The board I have from sparkfun for
>>> the Honeywell HMC1052L is a 4 pin-per-side 16-pin-LLC.  I'm capable of
>>> designing and ordering the adapter board, but I wouldn't get a chance
>>> to do it till tuesday night at the earliest, and I'm out of town for a
>>> week starting friday.
>>>
>>> This solderless socket might help with the prototyping:
>>> http://www.chiptool.net/adapter/plcc-1.htm
>>>
>>> That 1052L chip, by the way, I spent the weekend trying to use. 
>>> Unlike the HMC5843, the HMC1052L requires a 400 mA pulse for 2 uS to
>>> clear out any lingering magnetic fields, which requires an h-bridge or
>>> at least a totem-configured pair of FETs.  I started wiring it up, but
>>> after I've added an h-bridge chip, 2 capacitors, two resistors etc,
>>> the resulting cost and bulk make me think that I should have just
>>> started with the $19 5843, rather than "saving" via the $8.50 1052L.
>>>
>>> That BUB board looks nice, although I'm still super happy with my FTDI
>>> cable, just for compactness's sake.
>>>
>>> Adam Skory wrote:
>>>       
>>>> I want to order two of the HMC5843 3-axis compass chips in the hope
>>>> that someone will help me figure out how to surface mount the damned
>>>> things.
>>>>
>>>> (
>>>> http://parts.digikey.com/1/parts/1599656-sensor-magnetic-3-axis-20-lcc-hmc5843.html
>>>>
>>>> )
>>>>
>>>> Anyone else want some? It would be good to add them to today's digikey
>>>> bulk order.
>>>>
>>>> Also, I'm looking at getting some RBBB kits and a couple USB BUB
>>>> boards, separately from the digikey order, but it would good also to
>>>> know how many of those we should get.
>>>>
>>>> ( http://moderndevice.com/RBBB_revB.shtml and
>>>> http://www.moderndevice.com/connect.shtml )
>>>>
>>>> -Skory
>>>>
>>>>
>>>> ---------- Forwarded message ----------
>>>> From: miloh <froggytoad at gmail.com>
>>>> Date: Mon, Mar 23, 2009 at 10:52 AM
>>>> Subject: [Noisebridge-discuss] Re: March Digikey Bulk Order
>>>> To: noisebridge-discuss at lists.noisebridge.net
>>>>
>>>>
>>>> RE:  Digikey bulk order
>>>>
>>>> Correction:  didn't mean to suggest one needs to find dr_jesus on IRC,
>>>> the directions for being included are posted on the wiki:
>>>> https://www.noisebridge.net/wiki/Digikey_Bulk_Order
>>>>
>>>>
>>>>
>>>>
>>>> On Mon, Mar 23, 2009 at 9:40 AM, miloh <froggytoad at gmail.com> wrote:
>>>>  
>>>>         
>>>>> Friendly reminder: the March Digikey is going out by the afternoon,
>>>>> contact dr_jesus in IRC to get in on the action.
>>>>>
>>>>> -rma
>>>>>     
>>>>>           
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>>>>
>>>>   
>>>>         
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>
>
>   



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