The objective of this study was to assess the performance of a mobile sensor platform with ion-selective antimony electrodes (ISE) to determine pH on-the-go in a Brazilian tropical soil. The field experiments were carried out in a Cambisol in Piracicaba-SP, Brazil. To create pH variability, increasing doses (0, 1, 3, 5, 7 and 9 Mg ha^-1) of lime were added on the experimental plots (25 x 10 m) one year before the data acquisitions. To estimate soil pH levels we used a Mobile Sensor Platform (MSP - Veris Technologies, Salina, USA) with two ISE. In each plot, six on-the-go acquisitions were performed. Soil samples were collected at each of this acquisition points and sent to a laboratory for soil pH determination using two methods: H₂O solution and CaCl₂ 0,01 M solution. The analysis of pH data showed that treatments were effective to create variability in soil pH, with a minimum pH of 5.6 and maximum of 7.4 determined in H₂O solution. The average pH was higher in ISE determinations (6.87) and decreased using H₂O (6.53) and CaCl₂ (5.92) methods. The correlation between the readings taken on-the-go and in the laboratory were 0.90 and 0.91 using H₂O and CaCl₂ methods, respectively. These results revealed a great potential of using a MSP to estimate soil pH in Brazilian soils. Despite the good correlation coefficients, it is necessary to account for the difference between on-the-go and lab results before using the data to recommend variable rate lime applications.