Re: [轉錄][心得] 聯發科MTK晶片的 GPS衛星接收器

看板PDA作者CandyWind (Wind)時間18年前 (2007/06/18 02:17)推噓6(6推 0噓 0→)

留言6則, 2人參與討論串3/3 (看更多)

: PS:畢竟SirFIII也出來夠久了, MTK GPS的晶片較新,製程可以較先進, : 本來效能就該比較好,聯發科的晶片GPS在台灣賣,就算是效能較好且更省電. : MTK GPS 最大優點為較舊一代 0.13um 製程的 SiRFstarIII 省電. 最大弱點 : 為在訊號不佳情況下搜尋衛星速度慢; 樹下或市區冷開機或暖開機立可見得. : 由於省電廉價與高感度, 採聯發科 GPS 晶片之產品對大部分消費者應用已夠用. : 若應用環境多半是在像收訊不良高樓林立的台北市, 開機想早點定位的話, : SiRFstarIII 產品還是上選 *[1;37m推 *[33msklx*[m*[33m:定位速度其實是蠻大的關鍵... *[1;37m推 *[33mCandyWind*[m*[33m:目前Q818和M1000的官方規格，更新時間都為0.1s *[1;31m→ *[33mCandyWind*[m*[33m:個人實測M1000市區冷熱開機都比GR236還快，雖然沒 *[1;31m→ *[33mCandyWind*[m*[33m:而且大部份都是M1000有效衛星較多，並無定位不易?*[1;37m推 *[33mujj*[m*[33m:結論台灣還是用SIRF3較適合 ? *[1;37m推 *[33mdodow8889*[m*[33m:可是看樓上C大的使用心得感覺又不錯~可能要等多點 *[1;31m→ *[33mdodow8889*[m*[33m:得才能比較了..不過倒是希望台灣自家產品能更進步 *[1;31m→ *[33mdodow8889*[m*[33m:的絕對是消費者..畢竟價格能壓下來...^__^ 小弟回這篇不是想造成爭論，只是覺得有些部份與實測有差，不然像我這種最底層的user應該只有使用的份。其實我會考慮到MTK晶片的gps也是因看到mobile01『謎樣的晶片....』一文，所以一直在BT338和Q818猶豫不決，畢竟Q818我連代理商都沒聽過，不過後來考量品牌價位和01的網友的使用經驗，所以選Holux的產品。爬過的文： http://www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=67511 這篇主要可以看到MTK軌跡非常穩定。第一張巴黎街道：In dowtown Paris a sharp turn on the right on a fairly wide boulevard generates a strong multipath reaction on the SiRFstarIII receivers with the Nemerix NJ1030 v4, uBlox doing better but the best performance comes from the MTK chipset that is spot on 第二張圓環：Going round a roundabout under various underpasses, irregular tracks except on the Nemerix and MTK based receivers http://0rz.tw/8a2J1 這篇可以看到MTK定位迅速 For my test of the unit, I first of all gave it a thorough charge, and then powered it up and placed it on the office window sill. At this point I expected it to take a while to get a fix (as is customary in a 'cold start' scenario), but immediately, the BT-Q810 started to shine. The device actually found a good quality fix before my SiRF III unit had, which astounded me - I was up and running in around 30 seconds. http://www19.discuss.com.hk/viewthread.php?tid=3586148 這篇是香港的，路測還蠻詳細的。 http://www.pocketpcreviews.net/content/view/47/67/ 這篇介紹到MTK的高敏感度，不輸Sirf3，可能甚至超越在-158db時 The Qstarz uses the MTK chipset which is possibly even more sensitive (rated at -158dBm) than the SiRFstarIII and in static tests around the office this was proven by excellent reception results, even metres from the nearest window. Have a look at this screenshot which shows that we are still pulling in eight satellites while 5 m away from the nearest window ‧ Great sensitivity -- on a par or better than the SiRFstarIII at -158dBm -------------------------------------------------------- ps.值得一提的是官方規格上MTK -158dbm的敏感度可能沒有Sirf3 -159dbm還漂亮，但在上面實測好像也都沒輸掉，但最特別的應該是MTK晶片有很好的追蹤能力，窗邊定位後拿到距離窗邊幾公尺都還有很有機會定位到，所以進出隧道或高樓、高架橋等暫時遮蔽的區域受到的影響會相對的減少。以上是小弟之前爬文跟小小實測的心得，thanks -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 59.104.43.14

推

scer

06/18 02:56, , 1^F

06/18 02:56, 1^F

推

philipwen

06/18 11:16, , 2^F

06/18 11:16, 2^F

推

philipwen

06/18 11:16, , 3^F

06/18 11:16, 3^F